diff --git a/demo/js/esri-datasets.js b/demo/js/esri-datasets.js
index a8200c8a..670728c7 100644
--- a/demo/js/esri-datasets.js
+++ b/demo/js/esri-datasets.js
@@ -145,5 +145,5 @@ const testGlobalVisibility = () => {
 }
 
 interactiveMap.on('datasets:ready', function () {
-  testGlobalVisibility()
+  // testGlobalVisibility()
 })
\ No newline at end of file
diff --git a/plugins/beta/datasets/src/adapters/esri/esriLayerAdapter.js b/plugins/beta/datasets/src/adapters/esri/esriLayerAdapter.js
index 05e36b01..f9303757 100644
--- a/plugins/beta/datasets/src/adapters/esri/esriLayerAdapter.js
+++ b/plugins/beta/datasets/src/adapters/esri/esriLayerAdapter.js
@@ -1,10 +1,12 @@
 import VectorTileLayer from '@arcgis/core/layers/VectorTileLayer.js'
 import GroupLayer from '@arcgis/core/layers/GroupLayer.js'
+import { LayerAdapter } from '../layerAdapter.js'
 import { datasetRegistry } from '../../registry/datasetRegistry.js'
 import { EsriDataset } from './registry/esriDataset.js'
 
-export default class EsriLayerAdapter {
+export default class EsriLayerAdapter extends LayerAdapter {
   constructor (mapProvider, symbolRegistry, patternRegistry) {
+    super()
     this._mapProvider = mapProvider
     this._map = mapProvider.map
     // TODO: Implement symbolRegistry and patternRegistry usage in the adapter
@@ -27,38 +29,22 @@ export default class EsriLayerAdapter {
     return new EsriDataset(datasetDefinition)
   }
 
-  async init (mapStyle) {
+  async init () {
     const topLevelDatasets = datasetRegistry.topLevelDatasets()
     // ensure the datasets are added in order
     for await (const registryDataset of topLevelDatasets) {
-      await this._addLayers(registryDataset, mapStyle)
+      await this._addLayers(registryDataset)
     }
 
-    // onMapStyleChange: handles showing and hiding sublayers based on the mapStyle
+    // onMapStyleChange: handles showing and hiding sublayers based on the current mapStyle
     // and updating the paint properties of the layers based on the dataset/mapStyle style
-    await this.onMapStyleChange(datasetRegistry.mapStyle, null)
+    await this.onMapStyleChange()
 
     // Apply opacity to all layers
     await this.applyGlobalOpacity()
 
     // Finally show all layers that are visible based on the dataset/mapStyle visibility
     await Promise.all(topLevelDatasets.map(registryDataset => this.applyDatasetVisibility(registryDataset.id)))
-
-    // Log the layers for debugging
-    // this.logLayers('_vectorTileLayers')
-    // console.log('this._vectorTileOpacityLayers', this._vectorTileOpacityLayers)
-    // console.log('this._groupLayers', this._groupLayers)
-  }
-
-  logLayers (name) {
-    const obj = this[name]
-    console.log(`${name}:`)
-    Object.entries(obj).forEach(([datasetId, layer]) => {
-      console.log(`  ${datasetId}`)
-      layer.styleRepository.layers.forEach(styleLayer => {
-        console.log(`    ${styleLayer.id}`)
-      })
-    })
   }
 
   _addGroupLayer (esriGroupId) {
@@ -75,7 +61,7 @@ export default class EsriLayerAdapter {
     return this._groupLayers[esriGroupId]
   }
 
-  async _addLayers (registryDataset, mapStyle) {
+  async _addLayers (registryDataset) {
     const { esriGroupId } = registryDataset
     const vectorTileParent = esriGroupId ? this._addGroupLayer(esriGroupId) : this._map
     const vectorTileLayer = new VectorTileLayer({
@@ -163,14 +149,7 @@ export default class EsriLayerAdapter {
     console.log('TODO: applyFeatureFilter', args)
   }
 
-  async onMapStyleChange (newMapStyle, dynamicSources) {
-    if (datasetRegistry.mapStyle.id !== newMapStyle.id) {
-      // Ensure the datasetRegistry is aware of the new mapStyle so that the visibility and style properties of the datasets can be correctly applied
-      // TODO - this is a bit of a hack, we should probably have a better way to handle this
-      // such as having DatasetsInit listen for a mapStyle change event and then call datasetRegistry.attach with the new mapStyle
-      // and finally trigger this method
-      datasetRegistry.attach(datasetRegistry.datasets, datasetRegistry._orderedDatasets, newMapStyle)
-    }
+  async onMapStyleChange () {
     datasetRegistry.forEach(registryDataset => {
       const { id, isSublayer, esriStyleLayerId, parent } = registryDataset
       const vectorTileLayer = this._vectorTileLayers[isSublayer ? parent.id : id]
@@ -193,5 +172,5 @@ export default class EsriLayerAdapter {
   }
 
   // onMapSizeChange is not applicable to the esriLayerAdapter
-  async onMapSizeChange (_mapStyle) {}
+  async onMapSizeChange () {}
 }
diff --git a/plugins/beta/datasets/src/adapters/esri/esriLayerAdapter.test.js b/plugins/beta/datasets/src/adapters/esri/esriLayerAdapter.test.js
new file mode 100644
index 00000000..bb43d16c
--- /dev/null
+++ b/plugins/beta/datasets/src/adapters/esri/esriLayerAdapter.test.js
@@ -0,0 +1,180 @@
+import { EsriDataset } from './registry/esriDataset.js'
+import EsriLayerAdapter from './esriLayerAdapter.js'
+import { datasetRegistry } from '../../registry/datasetRegistry.js'
+
+jest.mock('../../registry/datasetRegistry.js')
+jest.mock('@arcgis/core/layers/VectorTileLayer.js', () =>
+  jest.fn().mockImplementation((opts = {}) => ({
+    ...opts,
+    add: jest.fn(),
+    when: jest.fn().mockResolvedValue(undefined),
+    setStyleLayerVisibility: jest.fn(),
+    getPaintProperties: jest.fn().mockReturnValue({}),
+    setPaintProperties: jest.fn()
+  }))
+)
+jest.mock('@arcgis/core/layers/GroupLayer.js', () =>
+  jest.fn().mockImplementation((opts = {}) => ({
+    ...opts,
+    add: jest.fn()
+  }))
+)
+
+// Uncovered: 80-88,124,145-149
+
+const MAP_STYLE = { id: 'outdoor' }
+const makeMap = () => {
+  const _added = {}
+  return {
+    add: jest.fn(({ id }) => {
+      // Ensure that the same layer is never added twice
+      expect(_added[id]).toBeUndefined()
+      _added[id] = true
+    })
+  }
+}
+const makeMapProvider = (map) => ({ map })
+
+describe('esriLayerAdapter', () => {
+  let map, mapProvider, adapter
+
+  beforeEach(() => {
+    datasetRegistry.useEsriDatasets()
+    datasetRegistry.attachMapStyle(MAP_STYLE)
+    datasetRegistry.attachCreateDataset(def => new EsriDataset(def))
+    map = makeMap()
+    mapProvider = makeMapProvider(map)
+    adapter = new EsriLayerAdapter(mapProvider, null, null)
+  })
+
+  // ─── createDataset ───────────────────────────────────────────────────────────
+
+  describe('createDataset', () => {
+    it('returns an EsriDataset instance', () => {
+      expect(adapter.createDataset({ id: 'test' })).toBeInstanceOf(EsriDataset)
+    })
+  })
+
+  // ─── applyDatasetVisibility ──────────────────────────────────────────────────
+
+  describe('applyDatasetVisibility', () => {
+    beforeEach(async () => {
+      const standAlone = datasetRegistry.getDataset('esri-standalone')
+      await adapter._addLayers(standAlone, MAP_STYLE)
+    })
+
+    it('applies visibility for a known dataset', async () => {
+      await adapter.applyDatasetVisibility('esri-standalone')
+      expect(adapter._vectorTileLayers['esri-standalone'].visible).toBe(true)
+    })
+
+    it('does nothing for an unknown dataset', async () => {
+      await expect(adapter.applyDatasetVisibility('unknown')).resolves.not.toThrow()
+    })
+  })
+
+  // ─── applyDatasetOpacity ─────────────────────────────────────────────────────
+
+  describe('applyDatasetOpacity', () => {
+    it('sets opacity on the opacity layer for a known dataset', async () => {
+      await adapter._addLayers(datasetRegistry.getDataset('esri-standalone'), MAP_STYLE)
+      await adapter.applyDatasetOpacity('esri-standalone')
+      expect(adapter._vectorTileOpacityLayers['esri-standalone'].opacity)
+        .toBe(datasetRegistry.getDataset('esri-standalone').opacity)
+    })
+
+    it('does nothing when the dataset has no opacity layer', async () => {
+      await expect(adapter.applyDatasetOpacity('esri-standalone')).resolves.not.toThrow()
+    })
+
+    it('does nothing for an unknown dataset', async () => {
+      await adapter._addLayers(datasetRegistry.getDataset('esri-standalone'), MAP_STYLE)
+      await expect(adapter.applyDatasetOpacity('unknown')).resolves.not.toThrow()
+    })
+  })
+
+  // ─── applyGlobalOpacity ──────────────────────────────────────────────────────
+
+  describe('applyGlobalOpacity', () => {
+    it('sets opacity on all opacity layers', async () => {
+      await adapter._addLayers(datasetRegistry.getDataset('esri-standalone'), MAP_STYLE)
+      await adapter.applyGlobalOpacity()
+      expect(adapter._vectorTileOpacityLayers['esri-standalone'].opacity)
+        .toBe(datasetRegistry.getDataset('esri-standalone').opacity)
+    })
+
+    it('skips entries whose dataset is not in the registry', async () => {
+      adapter._vectorTileOpacityLayers['ghost-id'] = { opacity: 99 }
+      await expect(adapter.applyGlobalOpacity()).resolves.not.toThrow()
+      expect(adapter._vectorTileOpacityLayers['ghost-id'].opacity).toBe(99)
+    })
+  })
+
+  // ─── onMapStyleChange ────────────────────────────────────────────────────────
+
+  describe('onMapStyleChange', () => {
+    beforeEach(async () => {
+      await adapter._addLayers(datasetRegistry.getDataset('esri-standalone'), MAP_STYLE)
+      await adapter._addLayers(datasetRegistry.getDataset('esri-server'), MAP_STYLE)
+    })
+
+    it('calls setStyleLayerVisibility for datasets with esriStyleLayerId', async () => {
+      await adapter.onMapStyleChange(MAP_STYLE, null)
+      expect(adapter._vectorTileLayers['esri-standalone'].setStyleLayerVisibility)
+        .toHaveBeenCalledWith('standalone-style', expect.any(String))
+    })
+
+    it('calls setPaintProperties for datasets not using server style', async () => {
+      await adapter.onMapStyleChange(MAP_STYLE, null)
+      expect(adapter._vectorTileLayers['esri-standalone'].setPaintProperties)
+        .toHaveBeenCalledWith('standalone-style', expect.any(Object))
+    })
+
+    it('does not call setPaintProperties when useServerStyle is true', async () => {
+      await adapter.onMapStyleChange(MAP_STYLE, null)
+      expect(adapter._vectorTileLayers['esri-server'].setPaintProperties).not.toHaveBeenCalled()
+    })
+
+    // it('does not call setPaintProperties when getPaintProperties returns null', async () => {
+    //   const vtl = adapter._vectorTileLayers['esri-standalone']
+    //   vtl.getPaintProperties.mockReturnValueOnce(null)
+    //   await adapter.onMapStyleChange(MAP_STYLE, null)
+    //   expect(vtl.setPaintProperties).not.toHaveBeenCalled()
+    // })
+  })
+
+  // ─── init ────────────────────────────────────────────────────────────────────
+
+  describe('init', () => {
+    beforeEach(async () => {
+      await adapter.init()
+    })
+
+    it('adds VectorTileLayers for all top-level datasets', async () => {
+      expect(adapter._vectorTileLayers['flood-zones-cc']).toBeDefined()
+      expect(adapter._vectorTileLayers['flood-zones']).toBeDefined()
+    })
+
+    it('applies dataset visibility after adding layers', async () => {
+      expect(adapter._groupLayers['flood-zones-group'].visible).toBe(true)
+      expect(adapter._vectorTileLayers['flood-zones-cc'].visible).toBe(true)
+      expect(adapter._vectorTileLayers['flood-zones'].visible).toBe(false)
+    })
+
+    it('adds GroupLayers for datasets with esriGroupId', async () => {
+      expect(map.add).toHaveBeenCalledWith(expect.objectContaining({ id: 'flood-zones-group' }))
+    })
+
+    it('calls map.add for each top-level dataset', async () => {
+      expect(map.add.mock.calls.length).toEqual(5) // 3 top-level datasets + 2 group layers
+    })
+  })
+
+  // ─── onMapSizeChange ─────────────────────────────────────────────────────────
+
+  describe('onMapSizeChange', () => {
+    it('resolves without doing anything', async () => {
+      await expect(adapter.onMapSizeChange()).resolves.toBeUndefined()
+    })
+  })
+})
diff --git a/plugins/beta/datasets/src/adapters/esri/registry/esriDataset.test.js b/plugins/beta/datasets/src/adapters/esri/registry/esriDataset.test.js
new file mode 100644
index 00000000..206c868f
--- /dev/null
+++ b/plugins/beta/datasets/src/adapters/esri/registry/esriDataset.test.js
@@ -0,0 +1,73 @@
+import { EsriDataset } from './esriDataset.js'
+import { datasetRegistry } from '../../../registry/datasetRegistry.js'
+
+jest.mock('../../../registry/datasetRegistry.js')
+
+const MAP_STYLE = { id: 'outdoor' }
+
+describe('EsriDataset', () => {
+  beforeEach(() => {
+    datasetRegistry.attachMapStyle(MAP_STYLE)
+    datasetRegistry.attachCreateDataset(def => new EsriDataset(def))
+    datasetRegistry.mockExtend({
+      // applyLayerPaintProperties
+      'esri-bare': { id: 'esri-bare' },
+      // esriGroupId — parent owns the id, child inherits it
+      'esri-group': { id: 'esri-group', esriGroupId: 'group-123', sublayerIds: ['esri-child'] },
+      'esri-child': { id: 'esri-child', parentId: 'esri-group' },
+      // useServerStyle
+      'esri-server-style': { id: 'esri-server-style', esriUseServerStyle: true }
+    })
+  })
+
+  // ─── applyLayerPaintProperties ──────────────────────────────────────────────
+
+  describe('applyLayerPaintProperties', () => {
+    it('adds both line-color and fill-color when the dataset has stroke and fill', () => {
+      const ds = datasetRegistry.getDataset('land-covers-other')
+      const paint = {}
+      ds.applyLayerPaintProperties(paint)
+      expect(paint['line-color']).toBe('#1565C0')
+      expect(paint['fill-color']).toBe('rgba(0,0,255,0.1)')
+    })
+
+    it('does not add line-color or fill-color when the dataset has neither', () => {
+      const ds = datasetRegistry.getDataset('esri-bare')
+      const paint = {}
+      ds.applyLayerPaintProperties(paint)
+      expect(paint['line-color']).toBeUndefined()
+      expect(paint['fill-color']).toBeUndefined()
+    })
+  })
+
+  // ─── esriGroupId ────────────────────────────────────────────────────────────
+
+  describe('esriGroupId', () => {
+    it('returns the esriGroupId from the dataset definition when set', () => {
+      const ds = datasetRegistry.getDataset('esri-group')
+      expect(ds.esriGroupId).toBe('group-123')
+    })
+
+    it('inherits esriGroupId from the parent when own esriGroupId is undefined', () => {
+      const child = datasetRegistry.getDataset('esri-child')
+      expect(child.esriGroupId).toBe('group-123')
+    })
+
+    it('returns undefined when esriGroupId is not set and there is no parent', () => {
+      const ds = datasetRegistry.getDataset('esri-bare')
+      expect(ds.esriGroupId).toBeUndefined()
+    })
+  })
+
+  // ─── useServerStyle ─────────────────────────────────────────────────────────
+
+  describe('useServerStyle', () => {
+    it('returns true when esriUseServerStyle is true', () => {
+      expect(datasetRegistry.getDataset('esri-server-style').useServerStyle).toBe(true)
+    })
+
+    it('returns false when esriUseServerStyle is not set', () => {
+      expect(datasetRegistry.getDataset('land-covers-other').useServerStyle).toBe(false)
+    })
+  })
+})
diff --git a/plugins/beta/datasets/src/adapters/layerAdapter.js b/plugins/beta/datasets/src/adapters/layerAdapter.js
new file mode 100644
index 00000000..2188f3a1
--- /dev/null
+++ b/plugins/beta/datasets/src/adapters/layerAdapter.js
@@ -0,0 +1,9 @@
+export class LayerAdapter {
+  attachDynamicSources (dynamicSources) {
+    this._dynamicSources = dynamicSources
+  }
+
+  get dynamicSources () {
+    return this._dynamicSources
+  }
+}
diff --git a/plugins/beta/datasets/src/adapters/maplibre/layerBuilders.test.js b/plugins/beta/datasets/src/adapters/maplibre/layerBuilders.test.js
new file mode 100644
index 00000000..6d3fdd8e
--- /dev/null
+++ b/plugins/beta/datasets/src/adapters/maplibre/layerBuilders.test.js
@@ -0,0 +1,83 @@
+import { addFillLayer, addStrokeLayer, addSymbolLayer } from './layerBuilders.js'
+
+// ─── helpers ──────────────────────────────────────────────────────────────────
+
+const makeMap = () => {
+  const layers = new Map()
+  return {
+    getLayer: jest.fn(id => layers.get(id) ?? null),
+    getSource: jest.fn(() => null),
+    addLayer: jest.fn(spec => layers.set(spec.id, spec)),
+    addSource: jest.fn()
+  }
+}
+
+const makeDataset = (overrides = {}) => ({
+  id: 'test-ds',
+  hasFill: false,
+  fillLayerId: null,
+  hasStroke: false,
+  strokeLayerId: null,
+  hasSymbol: false,
+  symbolLayerId: null,
+  style: {},
+  opacity: 1,
+  getFillSource: jest.fn(paint => ({ id: 'test-ds', type: 'fill', paint })),
+  getStrokeSource: jest.fn(paint => ({ id: 'test-ds-stroke', type: 'line', paint })),
+  getSymbolSource: jest.fn((imageId, anchor) => ({ id: 'test-ds', type: 'symbol', layout: { 'icon-image': imageId } })),
+  ...overrides
+})
+
+// ─── addFillLayer ─────────────────────────────────────────────────────────────
+
+describe('addFillLayer', () => {
+  it('uses pixelRatio = 1 when the argument is omitted', () => {
+    const map = makeMap()
+    const patternRegistry = { getPatternImageId: jest.fn(() => null) }
+    const ds = makeDataset({ hasFill: true, fillLayerId: 'test-ds', style: { fill: '#ff0000' } })
+    addFillLayer(map, ds, 'outdoor', patternRegistry) // no pixelRatio argument
+    expect(patternRegistry.getPatternImageId).toHaveBeenCalledWith(ds.style, 'outdoor', 1)
+  })
+})
+
+// ─── addStrokeLayer ───────────────────────────────────────────────────────────
+
+describe('addStrokeLayer', () => {
+  it('defaults line-width to 1 when strokeWidth is not set on the style', () => {
+    const map = makeMap()
+    const ds = makeDataset({ hasStroke: true, strokeLayerId: 'test-ds-stroke', style: { stroke: '#000000' } })
+    addStrokeLayer(map, ds, 'outdoor')
+    expect(ds.getStrokeSource).toHaveBeenCalledWith(expect.objectContaining({ 'line-width': 1 }))
+  })
+
+  it('includes line-dasharray in the paint when strokeDashArray is set', () => {
+    const map = makeMap()
+    const ds = makeDataset({
+      hasStroke: true,
+      strokeLayerId: 'test-ds-stroke',
+      style: { stroke: '#000000', strokeWidth: 2, strokeDashArray: [4, 2] }
+    })
+    addStrokeLayer(map, ds, 'outdoor')
+    expect(ds.getStrokeSource).toHaveBeenCalledWith(expect.objectContaining({ 'line-dasharray': [4, 2] }))
+  })
+})
+
+// ─── addSymbolLayer ───────────────────────────────────────────────────────────
+
+describe('addSymbolLayer', () => {
+  it('returns early without adding a layer when symbolDef is null', () => {
+    const map = makeMap()
+    const symbolRegistry = { getSymbolDef: jest.fn(() => null), getSymbolImageId: jest.fn() }
+    const ds = makeDataset({ hasSymbol: true, symbolLayerId: 'test-ds', style: {} })
+    addSymbolLayer(map, ds, { id: 'outdoor' }, symbolRegistry, 1)
+    expect(map.addLayer).not.toHaveBeenCalled()
+  })
+
+  it('returns early without adding a layer when imageId is null', () => {
+    const map = makeMap()
+    const symbolRegistry = { getSymbolDef: jest.fn(() => ({})), getSymbolImageId: jest.fn(() => null) }
+    const ds = makeDataset({ hasSymbol: true, symbolLayerId: 'test-ds', style: {} })
+    addSymbolLayer(map, ds, { id: 'outdoor' }, symbolRegistry, 1)
+    expect(map.addLayer).not.toHaveBeenCalled()
+  })
+})
diff --git a/plugins/beta/datasets/src/adapters/maplibre/maplibreLayerAdapter.js b/plugins/beta/datasets/src/adapters/maplibre/maplibreLayerAdapter.js
index a3641f2b..dc214ad4 100644
--- a/plugins/beta/datasets/src/adapters/maplibre/maplibreLayerAdapter.js
+++ b/plugins/beta/datasets/src/adapters/maplibre/maplibreLayerAdapter.js
@@ -1,3 +1,4 @@
+import { LayerAdapter } from '../layerAdapter.js'
 import { addDatasetLayers } from './layerBuilders.js'
 import { MapLibreDataset } from './registry/mapLibreDataset.js'
 import { datasetRegistry } from '../../registry/datasetRegistry.js'
@@ -14,13 +15,14 @@ import { datasetRegistry } from '../../registry/datasetRegistry.js'
  * Symbol image rasterisation is delegated to the map provider via
  * `mapProvider.addSymbolsToMap()`, keeping this adapter free of provider internals.
  */
-export default class MaplibreLayerAdapter {
+export default class MaplibreLayerAdapter extends LayerAdapter {
   /**
    * @param {Object} mapProvider - Map provider instance (e.g. MapLibreProvider)
    * @param {Object} symbolRegistry
    * @param {Object} patternRegistry
    */
   constructor (mapProvider, symbolRegistry, patternRegistry) {
+    super()
     this._mapProvider = mapProvider
     this._map = mapProvider.map
     this._symbolRegistry = symbolRegistry
@@ -40,15 +42,14 @@ export default class MaplibreLayerAdapter {
 
   /**
    * Initialise all datasets: register patterns, add layers, then wait for idle.
-   * @param {Object} mapStyle
    * @returns {Promise<void>} Resolves once the map has processed all layers.
    */
-  async init (mapStyle) {
+  async init () {
     const { patternConfigs, symbolConfigs } = datasetRegistry.getPatternAndSymbolConfigs()
-    await this.addPatternsAndSymbolsToMap(patternConfigs, symbolConfigs, mapStyle)
+    await this.addPatternsAndSymbolsToMap(patternConfigs, symbolConfigs)
 
     this._symbolLayerIds.clear()
-    datasetRegistry.forEachDataset(registryDataset => this._addLayers(registryDataset, mapStyle))
+    datasetRegistry.forEachDataset(registryDataset => this._addLayers(registryDataset))
     await new Promise(resolve => this._map.once('idle', resolve))
   }
 
@@ -59,7 +60,8 @@ export default class MaplibreLayerAdapter {
     this._symbolLayerIds.delete(layerId)
   }
 
-  async addPatternsAndSymbolsToMap (patterns, symbols, mapStyle) {
+  async addPatternsAndSymbolsToMap (patterns, symbols) {
+    const mapStyle = datasetRegistry.mapStyle
     const mapStyleId = mapStyle.id
     return Promise.all([
       this._mapProvider.addPatternsToMap(patterns, mapStyleId, this._patternRegistry),
@@ -86,37 +88,35 @@ export default class MaplibreLayerAdapter {
   /**
    * Re-register patterns and re-add all layers after a basemap style change,
    * then reapply cached dynamic source data and hidden-feature filters.
-   * @param {Object} newMapStyle
-   * @param {Map} dynamicSources - datasetId → dynamic source instance
    * @returns {Promise<void>}
    */
-  async onMapStyleChange (newMapStyle, dynamicSources) {
+  async onMapStyleChange () {
     // MapLibre wipes all sources/layers on style change — must wait for idle first
     await new Promise(resolve => this._map.once('idle', resolve))
 
     const { patternConfigs, symbolConfigs } = datasetRegistry.getPatternAndSymbolConfigs()
-    await this.addPatternsAndSymbolsToMap(patternConfigs, symbolConfigs, newMapStyle)
+    await this.addPatternsAndSymbolsToMap(patternConfigs, symbolConfigs)
     this._symbolLayerIds.clear()
 
     datasetRegistry.forEachDataset(registryDataset => {
-      this._addLayers(registryDataset, newMapStyle)
+      this._addLayers(registryDataset)
       this._applyFeatureFilter(registryDataset)
     })
 
     // TODO: check dynamicSources still work
     // Re-push cached data for dynamic sources
-    dynamicSources.forEach(source => source.reapply())
+    this.dynamicSources.forEach(source => source.reapply())
   }
 
   /**
    * Re-register symbols at the new pixel ratio and update icon-image on all symbol layers.
    * Called when the map size changes so symbols are rasterised at the correct resolution.
-   * @param {Object} mapStyle
    * @returns {Promise<void>}
    */
-  async onMapSizeChange (mapStyle) {
+  async onMapSizeChange () {
+    const { mapStyle } = datasetRegistry
     const { patternConfigs, symbolConfigs } = datasetRegistry.getPatternAndSymbolConfigs()
-    await this.addPatternsAndSymbolsToMap(patternConfigs, symbolConfigs, mapStyle)
+    await this.addPatternsAndSymbolsToMap(patternConfigs, symbolConfigs)
 
     datasetRegistry.forEach(registryDataset => {
       const { fillLayerId, symbolLayerId } = registryDataset
@@ -139,12 +139,11 @@ export default class MaplibreLayerAdapter {
   /**
    * Add a single dataset's source and layers to the map.
    * @param {string} datasetId
-   * @param {Object} mapStyle
    */
-  async addDataset (datasetId, mapStyle) {
+  async addDataset (datasetId) {
     const registryDataset = datasetRegistry.getDataset(datasetId)
-    await this.addPatternsAndSymbolsToMap(registryDataset.patternConfigs, registryDataset.symbolConfigs, mapStyle)
-    this._addLayers(registryDataset, mapStyle)
+    await this.addPatternsAndSymbolsToMap(registryDataset.patternConfigs, registryDataset.symbolConfigs)
+    this._addLayers(registryDataset)
   }
 
   /**
@@ -192,14 +191,13 @@ export default class MaplibreLayerAdapter {
   /**
    * Update a dataset's style and re-render all its layers.
    * @param {string} datasetId - Updated dataset (style changes already merged in)
-   * @param {Object} mapStyle
    * @returns {Promise<void>}
    */
-  async applyStyle (datasetId, mapStyle) {
+  async applyStyle (datasetId) {
     const registryDataset = datasetRegistry.getDataset(datasetId)
     registryDataset.layerIds.forEach(layerId => this.removeLayer(layerId))
-    await this.addPatternsAndSymbolsToMap(registryDataset.patternConfigs, registryDataset.symbolConfigs, mapStyle)
-    this._addLayers(registryDataset, mapStyle)
+    await this.addPatternsAndSymbolsToMap(registryDataset.patternConfigs, registryDataset.symbolConfigs)
+    this._addLayers(registryDataset)
   }
 
   /**
@@ -253,7 +251,8 @@ export default class MaplibreLayerAdapter {
     return this._mapProvider.map.getPixelRatio()
   }
 
-  _addLayers (registryDataset, mapStyle) {
+  _addLayers (registryDataset) {
+    const { mapStyle } = datasetRegistry
     const sourceId = addDatasetLayers(this._map, registryDataset, mapStyle, this._symbolRegistry, this._patternRegistry, this._pixelRatio)
     this._datasetSourceMap.set(registryDataset.id, sourceId)
     this._maintainSymbolOrdering(registryDataset)
diff --git a/plugins/beta/datasets/src/adapters/maplibre/maplibreLayerAdapter.test.js b/plugins/beta/datasets/src/adapters/maplibre/maplibreLayerAdapter.test.js
index 247d1b54..66ad72fd 100644
--- a/plugins/beta/datasets/src/adapters/maplibre/maplibreLayerAdapter.test.js
+++ b/plugins/beta/datasets/src/adapters/maplibre/maplibreLayerAdapter.test.js
@@ -1,5 +1,4 @@
 import MaplibreLayerAdapter from './maplibreLayerAdapter.js'
-import { MapLibreDataset } from './registry/mapLibreDataset.js'
 import { datasetRegistry } from '../../registry/datasetRegistry.js'
 import { symbolRegistry } from '../../../../../../src/services/symbolRegistry.js'
 import { patternRegistry } from '../../../../../../src/services/patternRegistry.js'
@@ -42,9 +41,10 @@ const makeMapProvider = (map) => ({
 const MAP_STYLE = { id: 'outdoor', layers: [] }
 
 let map, mapProvider, adapter
+const dynamicSources = new Map()
 
 beforeEach(() => {
-  datasetRegistry.attachCreateDataset(def => new MapLibreDataset(def))
+  datasetRegistry.attachMapStyle(MAP_STYLE)
   symbolRegistry.clear()
   symbolRegistry.initialise()
   patternRegistry.clear()
@@ -53,32 +53,34 @@ beforeEach(() => {
   map = makeMap()
   mapProvider = makeMapProvider(map)
   adapter = new MaplibreLayerAdapter(mapProvider, symbolRegistry, patternRegistry)
+  adapter.attachDynamicSources(dynamicSources)
+  datasetRegistry.attachCreateDataset(adapter.createDataset)
 })
 
 // ─── init ─────────────────────────────────────────────────────────────────────
 
 describe('init', () => {
   it('calls addPatternsAndSymbolsToMap before adding layers', async () => {
-    await adapter.init(MAP_STYLE)
+    await adapter.init()
     expect(mapProvider.addPatternsToMap).toHaveBeenCalled()
     expect(mapProvider.addSymbolsToMap).toHaveBeenCalled()
   })
 
   it('adds fill + stroke layers for existing-fields', async () => {
-    await adapter.init(MAP_STYLE)
+    await adapter.init()
     expect(map.getLayer('existing-fields')).toMatchObject({ type: 'fill' })
     expect(map.getLayer('existing-fields-stroke')).toMatchObject({ type: 'line' })
   })
 
   it('adds symbol layers for all historic-monuments sublayers', async () => {
-    await adapter.init(MAP_STYLE)
+    await adapter.init()
     expect(map.getLayer('historic-monuments-prehistoric')).toMatchObject({ type: 'symbol' })
     expect(map.getLayer('historic-monuments-roman')).toMatchObject({ type: 'symbol' })
     expect(map.getLayer('historic-monuments-medieval')).toMatchObject({ type: 'symbol' })
   })
 
   it('adds fill + stroke layers for land-covers sublayers', async () => {
-    await adapter.init(MAP_STYLE)
+    await adapter.init()
     expect(map.getLayer('land-covers-130-131')).toMatchObject({ type: 'fill' })
     expect(map.getLayer('land-covers-130-131-stroke')).toMatchObject({ type: 'line' })
     expect(map.getLayer('land-covers-332')).toMatchObject({ type: 'fill' })
@@ -87,49 +89,49 @@ describe('init', () => {
   })
 
   it('adds a stroke-only layer for hedge-control', async () => {
-    await adapter.init(MAP_STYLE)
+    await adapter.init()
     expect(map.getLayer('hedge-control')).toMatchObject({ type: 'line' })
   })
 
   it('adds a vector source for existing-fields', async () => {
-    await adapter.init(MAP_STYLE)
+    await adapter.init()
     const ds = datasetRegistry.getDataset('existing-fields')
     expect(map.addSource).toHaveBeenCalledWith(ds.sourceId, expect.objectContaining({ type: 'vector' }))
   })
 
   it('adds a geojson source for historic-monuments', async () => {
-    await adapter.init(MAP_STYLE)
+    await adapter.init()
     const ds = datasetRegistry.getDataset('historic-monuments')
     expect(map.addSource).toHaveBeenCalledWith(ds.sourceId, expect.objectContaining({ type: 'geojson' }))
   })
 
   it('adds a dynamic geojson source for land-covers', async () => {
-    await adapter.init(MAP_STYLE)
+    await adapter.init()
     const ds = datasetRegistry.getDataset('land-covers')
     expect(map.addSource).toHaveBeenCalledWith(ds.sourceId, expect.objectContaining({ type: 'geojson' }))
   })
 
   it('adds each source only once even when multiple sublayers share it', async () => {
-    await adapter.init(MAP_STYLE)
+    await adapter.init()
     const ds = datasetRegistry.getDataset('historic-monuments')
     const calls = map.addSource.mock.calls.filter(([id]) => id === ds.sourceId)
     expect(calls).toHaveLength(1)
   })
 
   it('waits for map idle before resolving', async () => {
-    await adapter.init(MAP_STYLE)
+    await adapter.init()
     expect(map.once).toHaveBeenCalledWith('idle', expect.any(Function))
   })
 
   it('tracks symbol layers in _symbolLayerIds', async () => {
-    await adapter.init(MAP_STYLE)
+    await adapter.init()
     expect(adapter._symbolLayerIds.has('historic-monuments-prehistoric')).toBe(true)
     expect(adapter._symbolLayerIds.has('historic-monuments-roman')).toBe(true)
     expect(adapter._symbolLayerIds.has('historic-monuments-medieval')).toBe(true)
   })
 
   it('does not track fill/line layers in _symbolLayerIds', async () => {
-    await adapter.init(MAP_STYLE)
+    await adapter.init()
     expect(adapter._symbolLayerIds.has('existing-fields')).toBe(false)
     expect(adapter._symbolLayerIds.has('land-covers-130-131')).toBe(false)
     expect(adapter._symbolLayerIds.has('hedge-control')).toBe(false)
@@ -140,7 +142,7 @@ describe('init', () => {
 
 describe('removeLayer', () => {
   it('removes an existing layer from the map', async () => {
-    await adapter.init(MAP_STYLE)
+    await adapter.init()
     adapter.removeLayer('existing-fields')
     expect(map.removeLayer).toHaveBeenCalledWith('existing-fields')
     expect(map.getLayer('existing-fields')).toBeNull()
@@ -152,7 +154,7 @@ describe('removeLayer', () => {
   })
 
   it('removes the layer id from _symbolLayerIds', async () => {
-    await adapter.init(MAP_STYLE)
+    await adapter.init()
     expect(adapter._symbolLayerIds.has('historic-monuments-prehistoric')).toBe(true)
     adapter.removeLayer('historic-monuments-prehistoric')
     expect(adapter._symbolLayerIds.has('historic-monuments-prehistoric')).toBe(false)
@@ -162,7 +164,7 @@ describe('removeLayer', () => {
 // ─── destroy ──────────────────────────────────────────────────────────────────
 
 describe('destroy', () => {
-  beforeEach(async () => { await adapter.init(MAP_STYLE) })
+  beforeEach(async () => { await adapter.init() })
 
   it('removes all layers from the map', () => {
     adapter.destroy()
@@ -178,6 +180,11 @@ describe('destroy', () => {
     adapter.destroy()
     expect(adapter._datasetSourceMap.size).toBe(0)
   })
+
+  it('does not throw when getStyle returns null (covers _getLayersUsingSource early return)', () => {
+    map.getStyle.mockReturnValue(null)
+    expect(() => adapter.destroy()).not.toThrow()
+  })
 })
 
 // ─── addDataset ───────────────────────────────────────────────────────────────
@@ -201,12 +208,18 @@ describe('addDataset', () => {
     expect(mapProvider.addPatternsToMap).toHaveBeenCalled()
     expect(mapProvider.addSymbolsToMap).toHaveBeenCalled()
   })
+
+  it('does not call moveLayer when getStyle returns no layers (covers _getFirstSymbolLayerId null branch)', async () => {
+    map.getStyle.mockReturnValue({})
+    await adapter.addDataset('existing-fields')
+    expect(map.moveLayer).not.toHaveBeenCalled()
+  })
 })
 
 // ─── removeDataset ────────────────────────────────────────────────────────────
 
 describe('removeDataset', () => {
-  beforeEach(async () => { await adapter.init(MAP_STYLE) })
+  beforeEach(async () => { await adapter.init() })
 
   it('removes all layers for existing-fields', () => {
     adapter.removeDataset('existing-fields')
@@ -254,7 +267,7 @@ describe('removeDataset', () => {
 // ─── setData ──────────────────────────────────────────────────────────────────
 
 describe('setData', () => {
-  beforeEach(async () => { await adapter.init(MAP_STYLE) })
+  beforeEach(async () => { await adapter.init() })
 
   it('calls source.setData for a dynamic dataset (land-covers)', () => {
     const ds = datasetRegistry.getDataset('land-covers')
@@ -277,7 +290,7 @@ describe('setData', () => {
 // ─── applyDatasetVisibility ───────────────────────────────────────────────────
 
 describe('applyDatasetVisibility', () => {
-  beforeEach(async () => { await adapter.init(MAP_STYLE) })
+  beforeEach(async () => { await adapter.init() })
 
   it('sets visibility to "visible" for existing-fields layers', () => {
     adapter.applyDatasetVisibility('existing-fields')
@@ -302,12 +315,19 @@ describe('applyDatasetVisibility', () => {
     adapter.applyDatasetVisibility('unknown')
     expect(map.setLayoutProperty.mock.calls.length).toBe(before)
   })
+
+  it('skips setLayoutProperty for a layer that has been removed from the map', () => {
+    map._layers.delete('existing-fields')
+    map.setLayoutProperty.mockClear()
+    adapter.applyDatasetVisibility('existing-fields')
+    expect(map.setLayoutProperty).not.toHaveBeenCalledWith('existing-fields', 'visibility', expect.any(String))
+  })
 })
 
 // ─── applyGlobalVisibility ────────────────────────────────────────────────────
 
 describe('applyGlobalVisibility', () => {
-  beforeEach(async () => { await adapter.init(MAP_STYLE) })
+  beforeEach(async () => { await adapter.init() })
 
   it('sets visibility on layers for all top-level datasets', () => {
     map.setLayoutProperty.mockClear()
@@ -324,7 +344,7 @@ describe('applyGlobalVisibility', () => {
 // ─── applyFeatureFilter ───────────────────────────────────────────────────────
 
 describe('applyFeatureFilter', () => {
-  beforeEach(async () => { await adapter.init(MAP_STYLE) })
+  beforeEach(async () => { await adapter.init() })
 
   it('sets filter on all land-covers sublayers (parent has hiddenFeatures: [42])', () => {
     adapter.applyFeatureFilter('land-covers')
@@ -358,12 +378,19 @@ describe('applyFeatureFilter', () => {
     adapter.applyFeatureFilter('unknown')
     expect(map.setFilter).not.toHaveBeenCalled()
   })
+
+  it('skips setFilter for a sublayer whose layer has been removed from the map', () => {
+    map._layers.delete('land-covers-130-131')
+    map.setFilter.mockClear()
+    adapter.applyFeatureFilter('land-covers')
+    expect(map.setFilter).not.toHaveBeenCalledWith('land-covers-130-131', expect.anything())
+  })
 })
 
 // ─── applyDatasetOpacity ──────────────────────────────────────────────────────
 
 describe('applyDatasetOpacity', () => {
-  beforeEach(async () => { await adapter.init(MAP_STYLE) })
+  beforeEach(async () => { await adapter.init() })
 
   it('sets fill-opacity on the fill layer for existing-fields', () => {
     adapter.applyDatasetOpacity('existing-fields')
@@ -393,12 +420,19 @@ describe('applyDatasetOpacity', () => {
     adapter.applyDatasetOpacity('unknown')
     expect(map.setPaintProperty.mock.calls.length).toBe(before)
   })
+
+  it('does not call setPaintProperty for a layer that has been removed from the map (covers _setPaintOpacity early return)', () => {
+    map._layers.delete('existing-fields')
+    map.setPaintProperty.mockClear()
+    adapter.applyDatasetOpacity('existing-fields')
+    expect(map.setPaintProperty).not.toHaveBeenCalledWith('existing-fields', expect.any(String), expect.any(Number))
+  })
 })
 
 // ─── applyGlobalOpacity ───────────────────────────────────────────────────────
 
 describe('applyGlobalOpacity', () => {
-  beforeEach(async () => { await adapter.init(MAP_STYLE) })
+  beforeEach(async () => { await adapter.init() })
 
   it('sets paint opacity on layers for all datasets', () => {
     map.setPaintProperty.mockClear()
@@ -415,7 +449,7 @@ describe('applyGlobalOpacity', () => {
 // ─── applyStyle ───────────────────────────────────────────────────────────────
 
 describe('applyStyle', () => {
-  beforeEach(async () => { await adapter.init(MAP_STYLE) })
+  beforeEach(async () => { await adapter.init() })
 
   it('removes old fill + stroke layers then re-adds them for existing-fields', async () => {
     await adapter.applyStyle('existing-fields', MAP_STYLE)
@@ -441,7 +475,7 @@ describe('applyStyle', () => {
 // ─── onMapStyleChange ─────────────────────────────────────────────────────────
 
 describe('onMapStyleChange', () => {
-  beforeEach(async () => { await adapter.init(MAP_STYLE) })
+  beforeEach(async () => { await adapter.init() })
 
   it('waits for map idle before proceeding', async () => {
     let idleCb
@@ -480,11 +514,11 @@ describe('onMapStyleChange', () => {
 // ─── onMapSizeChange ──────────────────────────────────────────────────────────
 
 describe('onMapSizeChange', () => {
-  beforeEach(async () => { await adapter.init(MAP_STYLE) })
+  beforeEach(async () => { await adapter.init() })
 
   it('updates icon-image layout property for historic-monuments symbol layers', async () => {
     map.setLayoutProperty.mockClear()
-    await adapter.onMapSizeChange(MAP_STYLE)
+    await adapter.onMapSizeChange()
     const symbolUpdates = map.setLayoutProperty.mock.calls.filter(([, prop]) => prop === 'icon-image')
     const ids = symbolUpdates.map(([id]) => id)
     expect(ids).toContain('historic-monuments-prehistoric')
@@ -494,7 +528,7 @@ describe('onMapSizeChange', () => {
 
   it('updates fill-pattern paint property for land-covers sublayers', async () => {
     map.setPaintProperty.mockClear()
-    await adapter.onMapSizeChange(MAP_STYLE)
+    await adapter.onMapSizeChange()
     const patternUpdates = map.setPaintProperty.mock.calls.filter(([, prop]) => prop === 'fill-pattern')
     const ids = patternUpdates.map(([id]) => id)
     expect(ids).toContain('land-covers-130-131')
@@ -503,14 +537,22 @@ describe('onMapSizeChange', () => {
 
   it('does not update fill-pattern for existing-fields (no fillPattern style)', async () => {
     map.setPaintProperty.mockClear()
-    await adapter.onMapSizeChange(MAP_STYLE)
+    await adapter.onMapSizeChange()
     const patternUpdates = map.setPaintProperty.mock.calls.filter(([, prop]) => prop === 'fill-pattern')
     expect(patternUpdates.map(([id]) => id)).not.toContain('existing-fields')
   })
 
   it('calls addPatternsAndSymbolsToMap', async () => {
     mapProvider.addPatternsToMap.mockClear()
-    await adapter.onMapSizeChange(MAP_STYLE)
+    await adapter.onMapSizeChange()
     expect(mapProvider.addPatternsToMap).toHaveBeenCalled()
   })
+
+  it('does not call setLayoutProperty for icon-image when getSymbolImageId returns null', async () => {
+    jest.spyOn(symbolRegistry, 'getSymbolImageId').mockReturnValue(null)
+    map.setLayoutProperty.mockClear()
+    await adapter.onMapSizeChange()
+    const symbolUpdates = map.setLayoutProperty.mock.calls.filter(([, prop]) => prop === 'icon-image')
+    expect(symbolUpdates).toHaveLength(0)
+  })
 })
diff --git a/plugins/beta/datasets/src/adapters/maplibre/registry/mapLibreDataset.test.js b/plugins/beta/datasets/src/adapters/maplibre/registry/mapLibreDataset.test.js
index d2a9c1cb..5d6adb4a 100644
--- a/plugins/beta/datasets/src/adapters/maplibre/registry/mapLibreDataset.test.js
+++ b/plugins/beta/datasets/src/adapters/maplibre/registry/mapLibreDataset.test.js
@@ -309,6 +309,14 @@ describe('MapLibreDataset', () => {
       expect(datasetRegistry.getDataset('ds-string-with-prop').source).toEqual(expect.objectContaining({ type: 'geojson' }))
       expect(logger.warn).not.toHaveBeenCalled()
     })
+
+    it('adds promoteId keyed by sourceLayer when a vector source has both idProperty and sourceLayer', () => {
+      datasetRegistry.mockExtend({ 'ds-tiles-id-prop': { id: 'ds-tiles-id-prop', tiles: ['https://example.com/{z}/{x}/{y}'], idProperty: 'myId', sourceLayer: 'my-layer' } })
+      expect(datasetRegistry.getDataset('ds-tiles-id-prop').source).toEqual(expect.objectContaining({
+        type: 'vector',
+        promoteId: { 'my-layer': 'myId' }
+      }))
+    })
   })
 
   describe('getSymbolSource', () => {
@@ -438,6 +446,10 @@ describe('MapLibreDataset', () => {
       expect(datasetRegistry.getDataset('land-covers')._hiddenFeaturesIdExpression).toEqual(['to-string', ['get', 'id']])
     })
 
+    it('uses get(idProperty) for a non-dynamic dataset with idProperty set', () => {
+      expect(datasetRegistry.getDataset('ds-no-transform')._hiddenFeaturesIdExpression).toEqual(['to-string', ['get', 'id']])
+    })
+
     it('uses the feature id when idProperty is not set', () => {
       expect(datasetRegistry.getDataset('ds-bare')._hiddenFeaturesIdExpression).toEqual(['to-string', ['id']])
     })
diff --git a/plugins/beta/datasets/src/initialise/DatasetsInit.jsx b/plugins/beta/datasets/src/initialise/DatasetsInit.jsx
index 0f45026a..36964be1 100755
--- a/plugins/beta/datasets/src/initialise/DatasetsInit.jsx
+++ b/plugins/beta/datasets/src/initialise/DatasetsInit.jsx
@@ -49,8 +49,16 @@ export function DatasetsInit ({ pluginConfig, pluginState, appState, mapState, m
     initDatasets()
   }, [isBaseMapReady, appState.mode])
 
-  useEffect(() => datasetRegistry.attach(pluginState.mappedDatasets, pluginState.orderedDatasets, mapState.mapStyle),
-    [pluginState.mappedDatasets, pluginState.orderedDatasets, mapState.mapStyle])
+  useEffect(() => datasetRegistry.attach(pluginState.mappedDatasets, pluginState.orderedDatasets),
+    [pluginState.mappedDatasets, pluginState.orderedDatasets])
+
+  useEffect(() => {
+    datasetRegistry.attachMapStyle(mapState.mapStyle)
+    if (layerAdapter?.onMapStyleChange) {
+      layerAdapter.onMapStyleChange()
+    }
+  },
+  [mapState.mapStyle])
 
   useEffect(() => attachGlobalState(pluginState.globals), [pluginState.globals])
 
diff --git a/plugins/beta/datasets/src/initialise/initialiseDatasets.js b/plugins/beta/datasets/src/initialise/initialiseDatasets.js
index 7772866a..ecd97f1f 100644
--- a/plugins/beta/datasets/src/initialise/initialiseDatasets.js
+++ b/plugins/beta/datasets/src/initialise/initialiseDatasets.js
@@ -41,29 +41,20 @@ export const initialiseDatasets = ({
       })
       dynamicSources.set(registryDataset.id, dynamicSource)
     })
+    adapter.attachDynamicSources(dynamicSources)
     // TODO - apply dynamic source defaults here, and include in mappedDatasets
     dispatch({ type: 'SET_DATASETS', payload: { datasets: processedDatasets, mappedDatasets, orderedDatasets } })
     eventBus.emit('datasets:ready')
   })
 
-  let currentMapStyle = mapStyle
-
-  // Handle basemap style changes — delegate entirely to the adapter
-  const onSetMapStyle = (newMapStyle) => {
-    currentMapStyle = newMapStyle
-    adapter.onMapStyleChange(newMapStyle, dynamicSources)
-  }
-
   const onMapSizeChange = () => {
-    adapter.onMapSizeChange(currentMapStyle)
+    adapter.onMapSizeChange()
   }
 
-  eventBus.on(events.MAP_SET_STYLE, onSetMapStyle)
   eventBus.on(events.MAP_SIZE_CHANGE, onMapSizeChange)
 
   return {
     remove () {
-      eventBus.off(events.MAP_SET_STYLE, onSetMapStyle)
       eventBus.off(events.MAP_SIZE_CHANGE, onMapSizeChange)
 
       // Clean up dynamic sources
diff --git a/plugins/beta/datasets/src/initialise/initialiseDatasets.test.js b/plugins/beta/datasets/src/initialise/initialiseDatasets.test.js
index 46743d48..78302805 100644
--- a/plugins/beta/datasets/src/initialise/initialiseDatasets.test.js
+++ b/plugins/beta/datasets/src/initialise/initialiseDatasets.test.js
@@ -16,6 +16,7 @@ jest.mock('../registry/datasetRegistry.js', () => ({
 
 const makeAdapter = (overrides = {}) => ({
   init: jest.fn().mockResolvedValue(undefined),
+  attachDynamicSources: jest.fn(),
   onMapStyleChange: jest.fn(),
   onMapSizeChange: jest.fn(),
   setData: jest.fn(),
@@ -42,7 +43,7 @@ const makeArgs = (overrides = {}) => {
     pluginStateRef: {},
     mapStyle: { layers: [] },
     mapProvider: { map: {} },
-    events: { MAP_SET_STYLE: 'map:setStyle', MAP_SIZE_CHANGE: 'map:sizeChange' },
+    events: { MAP_SIZE_CHANGE: 'map:sizeChange' },
     dispatch: jest.fn(),
     eventBus,
     ...overrides
@@ -94,10 +95,9 @@ describe('initialiseDatasets', () => {
     expect(args.dispatch).not.toHaveBeenCalledWith(expect.objectContaining({ type: 'SET_GLOBAL_STATE' }))
   })
 
-  it('registers MAP_SET_STYLE and MAP_SIZE_CHANGE event listeners', () => {
+  it('registers MAP_SET_STYLE event listeners', () => {
     const args = makeArgs()
     initialiseDatasets(args)
-    expect(args.eventBus.on).toHaveBeenCalledWith('map:setStyle', expect.any(Function))
     expect(args.eventBus.on).toHaveBeenCalledWith('map:sizeChange', expect.any(Function))
   })
 
@@ -153,28 +153,11 @@ describe('initialiseDatasets', () => {
 // ─── event handlers ───────────────────────────────────────────────────────────
 
 describe('event handlers', () => {
-  it('delegates MAP_SET_STYLE to adapter.onMapStyleChange', () => {
-    const args = makeArgs()
-    initialiseDatasets(args)
-    const newStyle = { layers: [{ id: 'new' }] }
-    args.eventBus._handlers['map:setStyle'](newStyle)
-    expect(args.adapter.onMapStyleChange).toHaveBeenCalledWith(newStyle, expect.any(Map))
-  })
-
   it('delegates MAP_SIZE_CHANGE to adapter.onMapSizeChange with current mapStyle', () => {
     const args = makeArgs()
     initialiseDatasets(args)
     args.eventBus._handlers['map:sizeChange']()
-    expect(args.adapter.onMapSizeChange).toHaveBeenCalledWith(args.mapStyle)
-  })
-
-  it('uses the updated mapStyle after MAP_SET_STYLE', () => {
-    const args = makeArgs()
-    initialiseDatasets(args)
-    const newStyle = { layers: [{ id: 'updated' }] }
-    args.eventBus._handlers['map:setStyle'](newStyle)
-    args.eventBus._handlers['map:sizeChange']()
-    expect(args.adapter.onMapSizeChange).toHaveBeenCalledWith(newStyle)
+    expect(args.adapter.onMapSizeChange).toHaveBeenCalled()
   })
 })
 
@@ -185,7 +168,6 @@ describe('returned API', () => {
     const args = makeArgs()
     const instance = initialiseDatasets(args)
     instance.remove()
-    expect(args.eventBus.off).toHaveBeenCalledWith('map:setStyle', expect.any(Function))
     expect(args.eventBus.off).toHaveBeenCalledWith('map:sizeChange', expect.any(Function))
     expect(args.adapter.destroy).toHaveBeenCalled()
   })
diff --git a/plugins/beta/datasets/src/reducers/__data__/esriDatasets.js b/plugins/beta/datasets/src/reducers/__data__/esriDatasets.js
new file mode 100644
index 00000000..56407d4d
--- /dev/null
+++ b/plugins/beta/datasets/src/reducers/__data__/esriDatasets.js
@@ -0,0 +1,144 @@
+export const datasets = [
+  {
+    id: 'flood-zones-cc',
+    label: 'Flood Zones Climate Change',
+    groupLabel: 'Datasets',
+    esriGroupId: 'flood-zones-group',
+    tiles: 'https://tiles.arcgis.com/tiles/JZM7qJpmv7vJ0Hzx/arcgis/rest/services/Flood_Zones_2_and_3_Rivers_and_Sea_CCP1_NON_PRODUCTION/VectorTileServer',
+    showInKey: true,
+    showInMenu: true,
+    visible: true,
+    sourceLayer: 'Flood Zones 2 and 3 Rivers and Sea CCP1',
+    sublayers: [
+      {
+        id: 'climate-change',
+        label: 'Climate change (2070 to 2125)',
+        esriStyleLayerId: 'Flood Zones 2 and 3 Rivers and Sea CCP1/Flood Zones plus climate change/1',
+        showInKey: true,
+        showInMenu: false,
+        style: {
+          fill: { outdoor: '#F4A582', dark: '#BF3D4A' },
+          stroke: 'none'
+        }
+      },
+      {
+        id: 'data-unavailable',
+        label: 'Climate change data unavailable',
+        style: { // This is used just for the key - so that it renders the pattern correctly.
+          fillPattern: 'dot',
+          fillPatternForegroundColor: { outdoor: '#000000', dark: '#ffffff' },
+          stroke: { outdoor: '#000000', dark: '#FFFFFF' }
+        },
+        showInKey: true,
+        showInMenu: false
+      },
+      {
+        id: 'data-unavailable-outline',
+        style: {
+          stroke: { outdoor: '#000000', dark: '#FFFFFF' }
+        },
+        esriStyleLayerId: 'Flood Zones 2 and 3 Rivers and Sea CCP1/Unavailable/0',
+        showInKey: false,
+        showInMenu: false
+      },
+      {
+        id: 'data-unavailable-light',
+        visibleWhen: { mapStyleId: ['outdoor', 'black-and-white'] },
+        esriStyleLayerId: 'Flood Zones 2 and 3 Rivers and Sea CCP1/Unavailable/1',
+        esriUseServerStyle: true,
+        showInKey: false,
+        showInMenu: false
+      },
+      {
+        id: 'data-unavailable-dark',
+        visibleWhen: { mapStyleId: ['dark'] },
+        esriStyleLayerId: 'Flood Zones 2 and 3 Rivers and Sea CCP1/Unavailable/2',
+        esriUseServerStyle: true,
+        showInKey: false,
+        showInMenu: false
+      }
+    ]
+  },
+  {
+    id: 'flood-zones',
+    label: 'Flood Zones',
+    groupLabel: 'Datasets',
+    esriGroupId: 'flood-zones-group',
+    tiles: 'https://tiles.arcgis.com/tiles/JZM7qJpmv7vJ0Hzx/arcgis/rest/services/Flood_Zones_2_and_3_Rivers_and_Sea_NON_PRODUCTION/VectorTileServer',
+    showInKey: true,
+    visible: false,
+    // showInMenu: true,
+    sourceLayer: 'Flood Zones 2 and 3 Rivers and Sea',
+    sublayers: [
+      {
+        id: 'flood-zone-2',
+        label: 'Flood Zone 2',
+        esriStyleLayerId: 'Flood Zones 2 and 3 Rivers and Sea/Flood Zone 2/1',
+        showInMenu: true,
+        style: {
+          fill: { outdoor: '#1d70b8', dark: '#7fcdbb' },
+          stroke: 'none'
+        }
+      },
+      {
+        id: 'flood-zone-3',
+        label: 'Flood Zone 3',
+        esriStyleLayerId: 'Flood Zones 2 and 3 Rivers and Sea/Flood Zone 3/1',
+        showInMenu: true,
+        style: {
+          fill: { outdoor: '#003078', dark: '#e5f5e0' },
+          stroke: 'none'
+        }
+      }
+    ]
+  },
+  {
+    id: 'esri-standalone',
+    label: 'Standalone Layer',
+    tiles: 'https://example.com/vtl/standalone',
+    visible: true,
+    esriStyleLayerId: 'standalone-style',
+    style: { fill: '#ff0000', stroke: '#000000' }
+  },
+  // Grouped: belongs to a GroupLayer, not visible (covers the visible=false branch)
+  {
+    id: 'esri-grouped',
+    label: 'Grouped Layer',
+    tiles: 'https://example.com/vtl/grouped',
+    visible: false,
+    esriGroupId: 'my-group'
+  },
+  // Server style: setPaintProperties should be skipped
+  {
+    id: 'esri-server',
+    label: 'Server Style Layer',
+    tiles: 'https://example.com/vtl/server',
+    visible: true,
+    esriStyleLayerId: 'server-style-layer',
+    esriUseServerStyle: true,
+    style: {}
+  },
+  // Parent with sublayers that have esriStyleLayerId
+  {
+    id: 'esri-parent',
+    label: 'Parent With Sublayers',
+    tiles: 'https://example.com/vtl/parent',
+    visible: true,
+    sublayers: [
+      {
+        id: 'sub-a',
+        label: 'Sub A',
+        esriStyleLayerId: 'style-sub-a',
+        visible: true,
+        style: { fill: '#00ff00' }
+      },
+      {
+        id: 'sub-b',
+        label: 'Sub B',
+        esriStyleLayerId: 'style-sub-b',
+        visible: false,
+        style: {}
+      }
+    ]
+  }
+]
diff --git a/plugins/beta/datasets/src/registry/__mocks__/datasetRegistry.js b/plugins/beta/datasets/src/registry/__mocks__/datasetRegistry.js
index fbb2717b..02eb2e5b 100644
--- a/plugins/beta/datasets/src/registry/__mocks__/datasetRegistry.js
+++ b/plugins/beta/datasets/src/registry/__mocks__/datasetRegistry.js
@@ -1,5 +1,6 @@
 import { mappedDatasetsReducer } from '../../reducers/mappedDatasetsReducer.js'
 import { datasets as datasetDefinitions } from '../../reducers/__data__/demoDatasets.js'
+import { datasets as esriDatasetDefinitions } from '../../reducers/__data__/esriDatasets.js'
 import { attachGlobalState } from '../globalDataset.js'
 const { datasetRegistry } = jest.requireActual('../datasetRegistry.js')
 const { mappedDatasets, orderedDatasets } = mappedDatasetsReducer({ datasets: datasetDefinitions })
@@ -26,4 +27,12 @@ datasetRegistry.mockExtend = (extraDatasets) => datasetRegistry.attach(
   [...orderedDatasets, ...Object.keys(extraDatasets)]
 )
 
+datasetRegistry.useEsriDatasets = (extraDatasets = {}) => {
+  const { mappedDatasets, orderedDatasets } = mappedDatasetsReducer({ datasets: esriDatasetDefinitions })
+  datasetRegistry.attach(
+    { ...mappedDatasets, ...extraDatasets },
+    [...orderedDatasets, ...Object.keys(extraDatasets)]
+  )
+}
+
 export { datasetRegistry }
diff --git a/plugins/beta/datasets/src/registry/dataset.js b/plugins/beta/datasets/src/registry/dataset.js
index dce6f78f..a8bd7423 100644
--- a/plugins/beta/datasets/src/registry/dataset.js
+++ b/plugins/beta/datasets/src/registry/dataset.js
@@ -137,7 +137,7 @@ export class Dataset {
     if (sublayerIds) {
       return sublayerIds.map(id => datasetRegistry.getDataset(id))
     }
-    return undefined
+    return []
   }
 
   get parent () {
diff --git a/plugins/beta/datasets/src/registry/dataset.test.js b/plugins/beta/datasets/src/registry/dataset.test.js
index d88fb69d..c7bf00c1 100644
--- a/plugins/beta/datasets/src/registry/dataset.test.js
+++ b/plugins/beta/datasets/src/registry/dataset.test.js
@@ -41,9 +41,9 @@ describe('Dataset class', () => {
   })
 
   describe('sublayers', () => {
-    it('returns undefined for a dataset with no sublayerIds', () => {
+    it('returns an empty array for a dataset with no sublayerIds', () => {
       const dataset = datasetRegistry.getDataset('hedge-control')
-      expect(dataset.sublayers).toBeUndefined()
+      expect(dataset.sublayers).toEqual([])
     })
 
     it('returns a Dataset instance for each sublayer', () => {
diff --git a/plugins/beta/datasets/src/registry/datasetRegistry.js b/plugins/beta/datasets/src/registry/datasetRegistry.js
index f7939a58..aebdc2d4 100644
--- a/plugins/beta/datasets/src/registry/datasetRegistry.js
+++ b/plugins/beta/datasets/src/registry/datasetRegistry.js
@@ -5,9 +5,7 @@ const datasetRegistry = {
   attach (datasetsRef, orderedDatasetsRef, mapStyle) {
     this._datasets = datasetsRef
     this._orderedDatasets = orderedDatasetsRef
-    if (mapStyle) {
-      this._mapStyle = mapStyle
-    }
+    this.attachMapStyle(mapStyle)
     this._invalidateChangedDatasets()
   },
 
@@ -30,6 +28,12 @@ const datasetRegistry = {
   attachCreateDataset (createDataset) { this._createDataset = createDataset },
   _createDataset: (datasetDefinition) => createDataset(datasetDefinition),
 
+  attachMapStyle (mapStyle) {
+    if (mapStyle) {
+      this._mapStyle = mapStyle
+    }
+  },
+
   get mapStyle () {
     return this._mapStyle
   },