diff --git a/src/Umbraco.Web.UI.Client/src/apps/backoffice/backoffice.context.ts b/src/Umbraco.Web.UI.Client/src/apps/backoffice/backoffice.context.ts
index 2446428a46..e4cdd92229 100644
--- a/src/Umbraco.Web.UI.Client/src/apps/backoffice/backoffice.context.ts
+++ b/src/Umbraco.Web.UI.Client/src/apps/backoffice/backoffice.context.ts
@@ -2,7 +2,7 @@ import { UmbContextToken } from '@umbraco-cms/backoffice/context-api';
 import { UmbBasicState, UmbStringState } from '@umbraco-cms/backoffice/observable-api';
 import { UmbExtensionManifestController, UmbExtensionsManifestController } from '@umbraco-cms/backoffice/extension-api';
 import { UmbControllerHost } from '@umbraco-cms/backoffice/controller-api';
-import { ManifestSection } from '@umbraco-cms/backoffice/extension-registry';
+import { ManifestSection, umbExtensionsRegistry } from '@umbraco-cms/backoffice/extension-registry';
 
 export class UmbBackofficeContext {
 	#activeSectionAlias = new UmbStringState(undefined);
@@ -13,7 +13,7 @@ export class UmbBackofficeContext {
 	public readonly allowedSections = this.#allowedSections.asObservable();
 
 	constructor(host: UmbControllerHost) {
-		new UmbExtensionsManifestController(host, 'section', null, (sections) => {
+		new UmbExtensionsManifestController(host, umbExtensionsRegistry, 'section', null, (sections) => {
 			this.#allowedSections.next([...sections]);
 		});
 	}
diff --git a/src/Umbraco.Web.UI.Client/src/libs/extension-api/controller/base-extensions-controller.test.ts b/src/Umbraco.Web.UI.Client/src/libs/extension-api/controller/base-extensions-controller.test.ts
index 5c153b7a6f..e40943e7db 100644
--- a/src/Umbraco.Web.UI.Client/src/libs/extension-api/controller/base-extensions-controller.test.ts
+++ b/src/Umbraco.Web.UI.Client/src/libs/extension-api/controller/base-extensions-controller.test.ts
@@ -24,13 +24,15 @@ class UmbTestExtensionController extends UmbBaseExtensionController {
 	}
 }
 
-const testExtensionRegistry = new UmbExtensionRegistry<ManifestWithDynamicConditions | ManifestCondition>();
+type myTestManifests = ManifestWithDynamicConditions | ManifestCondition;
+const testExtensionRegistry = new UmbExtensionRegistry<myTestManifests>();
 
 type PermittedControllerType = UmbTestExtensionController & {
 	manifest: Required<Pick<UmbTestExtensionController, 'manifest'>>;
 };
 
 class UmbTestExtensionsController extends UmbBaseExtensionsController<
+	myTestManifests,
 	'extension-type',
 	ManifestWithDynamicConditions,
 	UmbTestExtensionController,
diff --git a/src/Umbraco.Web.UI.Client/src/libs/extension-api/controller/base-extensions-controller.ts b/src/Umbraco.Web.UI.Client/src/libs/extension-api/controller/base-extensions-controller.ts
index 224142fff0..5bba5fb679 100644
--- a/src/Umbraco.Web.UI.Client/src/libs/extension-api/controller/base-extensions-controller.ts
+++ b/src/Umbraco.Web.UI.Client/src/libs/extension-api/controller/base-extensions-controller.ts
@@ -1,12 +1,11 @@
 import { map } from '@umbraco-cms/backoffice/external/rxjs';
-import {
+import type {
 	ManifestBase,
 	ManifestTypeMap,
 	SpecificManifestTypeOrManifestBase,
 	UmbBaseExtensionController,
 	UmbExtensionRegistry,
 } from '@umbraco-cms/backoffice/extension-api';
-import { ManifestTypes } from '@umbraco-cms/backoffice/extension-registry';
 import { UmbBaseController, UmbControllerHost } from '@umbraco-cms/backoffice/controller-api';
 
 export type PermittedControllerType<ControllerType extends { manifest: any }> = ControllerType & {
@@ -16,6 +15,7 @@ export type PermittedControllerType<ControllerType extends { manifest: any }> =
 /**
  */
 export abstract class UmbBaseExtensionsController<
+	ManifestTypes extends ManifestBase,
 	ManifestTypeName extends keyof ManifestTypeMap<ManifestTypes> | string,
 	ManifestType extends ManifestBase = SpecificManifestTypeOrManifestBase<ManifestTypes, ManifestTypeName>,
 	ControllerType extends UmbBaseExtensionController<ManifestType> = UmbBaseExtensionController<ManifestType>,
diff --git a/src/Umbraco.Web.UI.Client/src/libs/extension-api/controller/extensions-element-controller.ts b/src/Umbraco.Web.UI.Client/src/libs/extension-api/controller/extensions-element-controller.ts
index ce7c73de21..f5cf612a5d 100644
--- a/src/Umbraco.Web.UI.Client/src/libs/extension-api/controller/extensions-element-controller.ts
+++ b/src/Umbraco.Web.UI.Client/src/libs/extension-api/controller/extensions-element-controller.ts
@@ -4,19 +4,27 @@ import {
 	type ManifestTypeMap,
 	type SpecificManifestTypeOrManifestBase,
 	UmbExtensionElementController,
+	type UmbExtensionRegistry,
 } from '@umbraco-cms/backoffice/extension-api';
-import { type ManifestTypes, umbExtensionsRegistry } from '@umbraco-cms/backoffice/extension-registry';
 import type { UmbControllerHost } from '@umbraco-cms/backoffice/controller-api';
 
 /**
  */
 export class UmbExtensionsElementController<
+	ManifestTypes extends ManifestBase,
 	ManifestTypeName extends keyof ManifestTypeMap<ManifestTypes> | string = string,
 	ManifestType extends ManifestBase = SpecificManifestTypeOrManifestBase<ManifestTypes, ManifestTypeName>,
 	ControllerType extends UmbExtensionElementController<ManifestType> = UmbExtensionElementController<ManifestType>,
 	MyPermittedControllerType extends ControllerType = PermittedControllerType<ControllerType>
-> extends UmbBaseExtensionsController<ManifestTypeName, ManifestType, ControllerType, MyPermittedControllerType> {
+> extends UmbBaseExtensionsController<
+	ManifestTypes,
+	ManifestTypeName,
+	ManifestType,
+	ControllerType,
+	MyPermittedControllerType
+> {
 	//
+	#extensionRegistry;
 	private _defaultElement?: string;
 	#props?: Record<string, unknown>;
 
@@ -32,12 +40,14 @@ export class UmbExtensionsElementController<
 
 	constructor(
 		host: UmbControllerHost,
+		extensionRegistry: UmbExtensionRegistry<ManifestTypes>,
 		type: ManifestTypeName,
 		filter: undefined | null | ((manifest: ManifestType) => boolean),
 		onChange: (permittedManifests: Array<MyPermittedControllerType>, controller: MyPermittedControllerType) => void,
 		defaultElement?: string
 	) {
-		super(host, umbExtensionsRegistry, type, filter, onChange);
+		super(host, extensionRegistry, type, filter, onChange);
+		this.#extensionRegistry = extensionRegistry;
 		this._defaultElement = defaultElement;
 		this._init();
 	}
@@ -45,7 +55,7 @@ export class UmbExtensionsElementController<
 	protected _createController(manifest: ManifestType) {
 		const extController = new UmbExtensionElementController<ManifestType>(
 			this,
-			umbExtensionsRegistry,
+			this.#extensionRegistry,
 			manifest.alias,
 			this._extensionChanged,
 			this._defaultElement
diff --git a/src/Umbraco.Web.UI.Client/src/libs/extension-api/controller/extensions-manifest-controller.ts b/src/Umbraco.Web.UI.Client/src/libs/extension-api/controller/extensions-manifest-controller.ts
index d8ef617397..03c05468d0 100644
--- a/src/Umbraco.Web.UI.Client/src/libs/extension-api/controller/extensions-manifest-controller.ts
+++ b/src/Umbraco.Web.UI.Client/src/libs/extension-api/controller/extensions-manifest-controller.ts
@@ -4,32 +4,44 @@ import {
 	ManifestBase,
 	ManifestTypeMap,
 	SpecificManifestTypeOrManifestBase,
+	UmbExtensionRegistry,
 } from '@umbraco-cms/backoffice/extension-api';
-import { ManifestTypes, umbExtensionsRegistry } from '@umbraco-cms/backoffice/extension-registry';
 import { UmbControllerHost } from '@umbraco-cms/backoffice/controller-api';
 
 /**
  */
 export class UmbExtensionsManifestController<
+	ManifestTypes extends ManifestBase,
 	ManifestTypeName extends keyof ManifestTypeMap<ManifestTypes> | string,
 	ManifestType extends ManifestBase = SpecificManifestTypeOrManifestBase<ManifestTypes, ManifestTypeName>,
 	ControllerType extends UmbExtensionManifestController<ManifestType> = UmbExtensionManifestController<ManifestType>,
 	MyPermittedControllerType extends ControllerType = PermittedControllerType<ControllerType>
-> extends UmbBaseExtensionsController<ManifestTypeName, ManifestType, ControllerType, MyPermittedControllerType> {
+> extends UmbBaseExtensionsController<
+	ManifestTypes,
+	ManifestTypeName,
+	ManifestType,
+	ControllerType,
+	MyPermittedControllerType
+> {
+	//
+	#extensionRegistry: UmbExtensionRegistry<ManifestTypes>;
+
 	constructor(
 		host: UmbControllerHost,
+		extensionRegistry: UmbExtensionRegistry<ManifestTypes>,
 		type: ManifestTypeName,
 		filter: null | ((manifest: ManifestType) => boolean),
 		onChange: (permittedManifests: Array<MyPermittedControllerType>, controller: MyPermittedControllerType) => void
 	) {
-		super(host, umbExtensionsRegistry, type, filter, onChange);
+		super(host, extensionRegistry, type, filter, onChange);
+		this.#extensionRegistry = extensionRegistry;
 		this._init();
 	}
 
 	protected _createController(manifest: ManifestType) {
 		return new UmbExtensionManifestController<ManifestType>(
 			this,
-			umbExtensionsRegistry,
+			this.#extensionRegistry,
 			manifest.alias,
 			this._extensionChanged
 		) as ControllerType;
diff --git a/src/Umbraco.Web.UI.Client/src/packages/core/components/extension-slot/extension-slot.element.ts b/src/Umbraco.Web.UI.Client/src/packages/core/components/extension-slot/extension-slot.element.ts
index 7e625574a5..915a870b05 100644
--- a/src/Umbraco.Web.UI.Client/src/packages/core/components/extension-slot/extension-slot.element.ts
+++ b/src/Umbraco.Web.UI.Client/src/packages/core/components/extension-slot/extension-slot.element.ts
@@ -1,5 +1,9 @@
+import { type ManifestTypes, umbExtensionsRegistry } from '../../extension-registry/index.js';
 import { css, repeat, customElement, property, state } from '@umbraco-cms/backoffice/external/lit';
-import { UmbExtensionElementController, UmbExtensionsElementController } from '@umbraco-cms/backoffice/extension-api';
+import {
+	type UmbExtensionElementController,
+	UmbExtensionsElementController,
+} from '@umbraco-cms/backoffice/extension-api';
 import { UmbLitElement } from '@umbraco-cms/internal/lit-element';
 
 export type InitializedExtension = { alias: string; weight: number; component: HTMLElement | null };
@@ -17,7 +21,7 @@ export type InitializedExtension = { alias: string; weight: number; component: H
 // TODO: Make property that reveals the amount of displayed/permitted extensions.
 @customElement('umb-extension-slot')
 export class UmbExtensionSlotElement extends UmbLitElement {
-	#extensionsController?: UmbExtensionsElementController;
+	#extensionsController?: UmbExtensionsElementController<ManifestTypes>;
 
 	@state()
 	private _permittedExts: Array<UmbExtensionElementController> = [];
@@ -51,17 +55,12 @@ export class UmbExtensionSlotElement extends UmbLitElement {
 
 	private _observeExtensions() {
 		this.#extensionsController?.destroy();
-		if (this.type === 'treeItem') {
-			console.log('observe', this.type, this.defaultElement);
-		}
 		this.#extensionsController = new UmbExtensionsElementController(
 			this,
+			umbExtensionsRegistry,
 			this.type,
 			this.filter,
 			(extensionControllers) => {
-				if (extensionControllers[0].manifest?.type === 'treeItem') {
-					console.log('extensionControllers', extensionControllers);
-				}
 				this._permittedExts = extensionControllers;
 			},
 			this.defaultElement
diff --git a/src/Umbraco.Web.UI.Client/src/packages/core/section/section-default.element.ts b/src/Umbraco.Web.UI.Client/src/packages/core/section/section-default.element.ts
index c64477eaf2..07e0c56039 100644
--- a/src/Umbraco.Web.UI.Client/src/packages/core/section/section-default.element.ts
+++ b/src/Umbraco.Web.UI.Client/src/packages/core/section/section-default.element.ts
@@ -7,6 +7,7 @@ import {
 	ManifestSectionSidebarApp,
 	ManifestSectionSidebarAppMenuKind,
 	UmbSectionExtensionElement,
+	umbExtensionsRegistry,
 } from '@umbraco-cms/backoffice/extension-registry';
 import type { UmbRoute } from '@umbraco-cms/backoffice/router';
 import { UmbLitElement } from '@umbraco-cms/internal/lit-element';
@@ -44,7 +45,7 @@ export class UmbSectionDefaultElement extends UmbLitElement implements UmbSectio
 	constructor() {
 		super();
 
-		new UmbExtensionsElementController(this, 'sectionSidebarApp', null, (sidebarApps) => {
+		new UmbExtensionsElementController(this, umbExtensionsRegistry, 'sectionSidebarApp', null, (sidebarApps) => {
 			const oldValue = this._sidebarApps;
 			this._sidebarApps = sidebarApps;
 			this.requestUpdate('_sidebarApps', oldValue);
diff --git a/src/Umbraco.Web.UI.Client/src/packages/core/section/section-main-views/section-main-views.element.ts b/src/Umbraco.Web.UI.Client/src/packages/core/section/section-main-views/section-main-views.element.ts
index 4c01a94fde..0279cbe2ab 100644
--- a/src/Umbraco.Web.UI.Client/src/packages/core/section/section-main-views/section-main-views.element.ts
+++ b/src/Umbraco.Web.UI.Client/src/packages/core/section/section-main-views/section-main-views.element.ts
@@ -6,6 +6,7 @@ import {
 	ManifestSectionView,
 	UmbDashboardExtensionElement,
 	UmbSectionViewExtensionElement,
+	umbExtensionsRegistry,
 } from '@umbraco-cms/backoffice/extension-registry';
 import { UmbExtensionsManifestController, createExtensionElement } from '@umbraco-cms/backoffice/extension-api';
 import { UmbLitElement } from '@umbraco-cms/internal/lit-element';
@@ -35,12 +36,12 @@ export class UmbSectionMainViewElement extends UmbLitElement {
 	constructor() {
 		super();
 
-		new UmbExtensionsManifestController(this, 'dashboard', null, (dashboards) => {
+		new UmbExtensionsManifestController(this, umbExtensionsRegistry, 'dashboard', null, (dashboards) => {
 			this._dashboards = dashboards.map((dashboard) => dashboard.manifest);
 			this.#createRoutes();
 		});
 
-		new UmbExtensionsManifestController(this, 'sectionView', null, (views) => {
+		new UmbExtensionsManifestController(this, umbExtensionsRegistry, 'sectionView', null, (views) => {
 			this._views = views.map((view) => view.manifest);
 			this.#createRoutes();
 		});