diff --git a/.eslintrc.js b/.eslintrc.js
index ad524b5..d6a599c 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -66,6 +66,7 @@ module.exports = {
           },
         ],
         '@typescript-eslint/no-unused-vars': 'off',
+        '@typescript-eslint/no-floating-promises': 'warn',
       },
     },
     {
diff --git a/packages/benchmarks/src/index.tsx b/packages/benchmarks/src/index.tsx
index 11361c5..a13045a 100644
--- a/packages/benchmarks/src/index.tsx
+++ b/packages/benchmarks/src/index.tsx
@@ -106,6 +106,6 @@ async function test1() {
   iterateOnSequence()
 }
 
-test1().then(() => {
+void test1().then(() => {
   console.log('test1 done')
 })
diff --git a/packages/browser-bundles/devEnv/build.ts b/packages/browser-bundles/devEnv/build.ts
index eb87eb0..f76894a 100644
--- a/packages/browser-bundles/devEnv/build.ts
+++ b/packages/browser-bundles/devEnv/build.ts
@@ -35,14 +35,14 @@ function createBundles(watch: boolean) {
   //   format: 'iife',
   // })
 
-  build({
+  void build({
     ...esbuildConfig,
     entryPoints: [path.join(pathToPackage, 'src/core-and-studio.ts')],
     outfile: path.join(pathToPackage, 'dist/core-and-studio.js'),
     format: 'iife',
   })
 
-  build({
+  void build({
     ...esbuildConfig,
     entryPoints: [path.join(pathToPackage, 'src/core-only.ts')],
     outfile: path.join(pathToPackage, 'dist/core-only.min.js'),
diff --git a/packages/dataverse/devEnv/build.ts b/packages/dataverse/devEnv/build.ts
index 063e614..e0998be 100644
--- a/packages/dataverse/devEnv/build.ts
+++ b/packages/dataverse/devEnv/build.ts
@@ -17,7 +17,7 @@ function createBundles(watch: boolean) {
     conditions: ['browser', 'node'],
   }
 
-  build({
+  void build({
     ...esbuildConfig,
     outfile: path.join(pathToPackage, 'dist/index.js'),
     format: 'cjs',
diff --git a/packages/playground/src/shared/image/index.tsx b/packages/playground/src/shared/image/index.tsx
index 7b445de..e216aa1 100644
--- a/packages/playground/src/shared/image/index.tsx
+++ b/packages/playground/src/shared/image/index.tsx
@@ -53,7 +53,7 @@ const ImageTypeExample: React.FC<{}> = (props) => {
       onClick={() => {
         if (sheet.sequence.position === 0) {
           sheet.sequence.position = 0
-          sheet.sequence.play()
+          void sheet.sequence.play()
         } else {
           sheet.sequence.position = 0
         }
@@ -64,6 +64,10 @@ const ImageTypeExample: React.FC<{}> = (props) => {
   )
 }
 
-project.ready.then(() => {
-  render(<ImageTypeExample />, document.getElementById('root'))
-})
+project.ready
+  .then(() => {
+    render(<ImageTypeExample />, document.getElementById('root'))
+  })
+  .catch((err) => {
+    console.error(err)
+  })
diff --git a/packages/playground/src/shared/notifications/index.tsx b/packages/playground/src/shared/notifications/index.tsx
index 00bd26f..5d2f0d8 100644
--- a/packages/playground/src/shared/notifications/index.tsx
+++ b/packages/playground/src/shared/notifications/index.tsx
@@ -7,7 +7,7 @@ import {Scene} from './Scene'
 studio.initialize()
 
 // trigger warning notification
-getProject('Sample project').sheet('Scene').sequence.play()
+void getProject('Sample project').sheet('Scene').sequence.play()
 
 // fire an info notification
 notify.info(
@@ -16,7 +16,7 @@ notify.info(
     '(and all others) at the start of index.tsx. You can also see examples of success and warnign notifications.',
 )
 
-getProject('Sample project').ready.then(() => {
+void getProject('Sample project').ready.then(() => {
   // fire a success notification on project load
   notify.success(
     'Project loaded!',
diff --git a/packages/playground/src/shared/theatric/index.tsx b/packages/playground/src/shared/theatric/index.tsx
index ce0cc13..6d2b273 100644
--- a/packages/playground/src/shared/theatric/index.tsx
+++ b/packages/playground/src/shared/theatric/index.tsx
@@ -3,7 +3,7 @@ import {render} from 'react-dom'
 import React, {useState} from 'react'
 import state from './state.json'
 
-initialize({state})
+void initialize({state})
 
 function SomeComponent({id}: {id: string}) {
   const {foo, $get, $set} = useControls(
diff --git a/packages/playground/src/tests/r3f-stress-test/App.tsx b/packages/playground/src/tests/r3f-stress-test/App.tsx
index c5a83ae..43ed8f7 100644
--- a/packages/playground/src/tests/r3f-stress-test/App.tsx
+++ b/packages/playground/src/tests/r3f-stress-test/App.tsx
@@ -76,7 +76,7 @@ function App() {
   const bg = bgs[bgIndex]
   const project = getProject('SpaceStress', {state})
   const sheet = project.sheet('Scene')
-  project.ready.then(() => sheet.sequence.play({iterationCount: Infinity}))
+  void project.ready.then(() => sheet.sequence.play({iterationCount: Infinity}))
 
   const allPropsObj = sheet.object('All Props Tester', allPropsObjectConfig)
   console.log('allPropsObj', allPropsObj)
diff --git a/packages/playground/src/tests/reading-obj-value/index.tsx b/packages/playground/src/tests/reading-obj-value/index.tsx
index 4886def..16183ea 100644
--- a/packages/playground/src/tests/reading-obj-value/index.tsx
+++ b/packages/playground/src/tests/reading-obj-value/index.tsx
@@ -39,13 +39,13 @@ const elements = new Array(TOTAL_ELEMENTS).fill(0).map((_, idx) => {
   return {el, sheet, obj}
 })
 
-project.ready.then(() => {
+void project.ready.then(() => {
   // select the playback controls obj so it shows as a tweakable control
   studio.setSelection([playbackControlObj])
   for (let i = 0; i < elements.length; i++) {
     const sheet = elements[i].sheet
     sheet.sequence.position = i * TOTAL_ELEMENTS_R * 5
-    sheet.sequence.play({
+    void sheet.sequence.play({
       iterationCount: Infinity,
     })
   }
diff --git a/packages/r3f/devEnv/bundle.ts b/packages/r3f/devEnv/bundle.ts
index 7518abd..6a4b1be 100644
--- a/packages/r3f/devEnv/bundle.ts
+++ b/packages/r3f/devEnv/bundle.ts
@@ -8,11 +8,10 @@ const definedGlobals = {
   'process.env.NODE_ENV': JSON.stringify('production'),
 }
 
-createBundles()
+void createBundles()
 
 async function createBundles() {
-  createMainBundle()
-  createExtensionBundle()
+  await Promise.all([createMainBundle(), createExtensionBundle()])
 
   async function createMainBundle() {
     const pathToEntry = path.join(__dirname, '../src/index.ts')
diff --git a/packages/react/devEnv/build.ts b/packages/react/devEnv/build.ts
index 599d720..69c3856 100644
--- a/packages/react/devEnv/build.ts
+++ b/packages/react/devEnv/build.ts
@@ -24,7 +24,7 @@ const definedGlobals = {
   global: 'window',
 }
 
-function createBundles(watch: boolean) {
+async function createBundles(watch: boolean) {
   const pathToPackage = path.join(__dirname, '../')
   const esbuildConfig: Parameters<typeof build>[0] = {
     entryPoints: [path.join(pathToPackage, 'src/index.ts')],
@@ -39,7 +39,7 @@ function createBundles(watch: boolean) {
     plugins: [externalPlugin([/^[\@a-zA-Z]+/])],
   }
 
-  build({
+  await build({
     ...esbuildConfig,
     outfile: path.join(pathToPackage, 'dist/index.js'),
     format: 'cjs',
@@ -52,4 +52,4 @@ function createBundles(watch: boolean) {
   // })
 }
 
-createBundles(false)
+void createBundles(false)
diff --git a/packages/theatric/devEnv/build.ts b/packages/theatric/devEnv/build.ts
index cb4c484..fad8649 100644
--- a/packages/theatric/devEnv/build.ts
+++ b/packages/theatric/devEnv/build.ts
@@ -24,7 +24,7 @@ const definedGlobals = {
   global: 'window',
 }
 
-function createBundles(watch: boolean) {
+async function createBundles(watch: boolean) {
   const pathToPackage = path.join(__dirname, '../')
   const pkgJson = require(path.join(pathToPackage, 'package.json'))
   const listOfDependencies = Object.keys(pkgJson.dependencies || {})
@@ -52,7 +52,7 @@ function createBundles(watch: boolean) {
     ],
   }
 
-  build({
+  await build({
     ...esbuildConfig,
     outfile: path.join(pathToPackage, 'dist/index.js'),
     format: 'cjs',
@@ -65,4 +65,4 @@ function createBundles(watch: boolean) {
   // })
 }
 
-createBundles(false)
+void createBundles(false)
diff --git a/theatre/core/src/projects/Project.ts b/theatre/core/src/projects/Project.ts
index 1b0e5c1..e4d5895 100644
--- a/theatre/core/src/projects/Project.ts
+++ b/theatre/core/src/projects/Project.ts
@@ -196,29 +196,34 @@ export default class Project {
     }
     this._studio = studio
 
-    studio.initialized.then(async () => {
-      await initialiseProjectState(studio, this, this.config.state)
+    studio.initialized
+      .then(async () => {
+        await initialiseProjectState(studio, this, this.config.state)
 
-      this._pointerProxies.historic.setPointer(
-        studio.atomP.historic.coreByProject[this.address.projectId],
-      )
-      this._pointerProxies.ahistoric.setPointer(
-        studio.atomP.ahistoric.coreByProject[this.address.projectId],
-      )
-      this._pointerProxies.ephemeral.setPointer(
-        studio.atomP.ephemeral.coreByProject[this.address.projectId],
-      )
+        this._pointerProxies.historic.setPointer(
+          studio.atomP.historic.coreByProject[this.address.projectId],
+        )
+        this._pointerProxies.ahistoric.setPointer(
+          studio.atomP.ahistoric.coreByProject[this.address.projectId],
+        )
+        this._pointerProxies.ephemeral.setPointer(
+          studio.atomP.ephemeral.coreByProject[this.address.projectId],
+        )
 
-      // asset storage has to be initialized after the pointers are set
-      studio
-        .createAssetStorage(this, this.config.assets?.baseUrl)
-        .then((assetStorage) => {
-          this.assetStorage = assetStorage
-          this._assetStorageReadyDeferred.resolve(undefined)
-        })
+        // asset storage has to be initialized after the pointers are set
+        await studio
+          .createAssetStorage(this, this.config.assets?.baseUrl)
+          .then((assetStorage) => {
+            this.assetStorage = assetStorage
+            this._assetStorageReadyDeferred.resolve(undefined)
+          })
 
-      this._studioReadyDeferred.resolve(undefined)
-    })
+        this._studioReadyDeferred.resolve(undefined)
+      })
+      .catch((err) => {
+        console.error(err)
+        throw err
+      })
   }
 
   get isAttachedToStudio() {
diff --git a/theatre/core/src/sequences/TheatreSequence.ts b/theatre/core/src/sequences/TheatreSequence.ts
index 0121810..9c5d630 100644
--- a/theatre/core/src/sequences/TheatreSequence.ts
+++ b/theatre/core/src/sequences/TheatreSequence.ts
@@ -354,7 +354,9 @@ async function resolveAudioBuffer(args: IAttachAudioArgs): Promise<{
     }
     return new Promise<AudioContext>((resolve) => {
       const listener = () => {
-        ctx.resume()
+        ctx.resume().catch((err) => {
+          console.error(err)
+        })
       }
 
       const eventsToHookInto: Array<keyof WindowEventMap> = [
@@ -412,6 +414,7 @@ async function resolveAudioBuffer(args: IAttachAudioArgs): Promise<{
 
     const audioContext = await audioContextPromise
 
+    // eslint-disable-next-line @typescript-eslint/no-floating-promises
     audioContext.decodeAudioData(
       arrayBuffer,
       decodedBufferDeferred.resolve,
diff --git a/theatre/devEnv/bundle.ts b/theatre/devEnv/bundle.ts
index 5e3b9df..7396b41 100644
--- a/theatre/devEnv/bundle.ts
+++ b/theatre/devEnv/bundle.ts
@@ -1,3 +1,3 @@
 import {createBundles} from './createBundles'
 
-createBundles(false)
+void createBundles(false)
diff --git a/theatre/devEnv/watch.ts b/theatre/devEnv/watch.ts
index edd9759..71de62a 100644
--- a/theatre/devEnv/watch.ts
+++ b/theatre/devEnv/watch.ts
@@ -1,3 +1,3 @@
 import {createBundles} from './createBundles'
 
-createBundles(true)
+void createBundles(true)
diff --git a/theatre/shared/src/testUtils.ts b/theatre/shared/src/testUtils.ts
index 9c51b75..bc3d443 100644
--- a/theatre/shared/src/testUtils.ts
+++ b/theatre/shared/src/testUtils.ts
@@ -28,7 +28,7 @@ const defaultProps = {
 let lastProjectN = 0
 
 const studio = getStudio()!
-studio.initialize({usePersistentStorage: false})
+void studio.initialize({usePersistentStorage: false})
 
 export async function setupTestSheet(sheetState: SheetState_Historic) {
   const projectState: ProjectState_Historic = {
diff --git a/theatre/studio/src/Studio.ts b/theatre/studio/src/Studio.ts
index e1bd052..12ddb0d 100644
--- a/theatre/studio/src/Studio.ts
+++ b/theatre/studio/src/Studio.ts
@@ -203,7 +203,9 @@ export class Studio {
 
     if (process.env.NODE_ENV !== 'test') {
       this.ui.render()
-      checkForUpdates()
+      checkForUpdates().catch((err) => {
+        console.error(err)
+      })
     }
   }
 
@@ -266,7 +268,7 @@ export class Studio {
     return this._coreAtom.pointer.core
   }
 
-  extend(extension: IExtension) {
+  extend(extension: IExtension, opts?: {__experimental_reconfigure?: boolean}) {
     if (!extension || typeof extension !== 'object') {
       throw new Error(`Extensions must be JS objects`)
     }
@@ -275,20 +277,27 @@ export class Studio {
       throw new Error(`extension.id must be a string`)
     }
 
+    const reconfigure = opts?.__experimental_reconfigure === true
+
     const extensionId = extension.id
 
     const prevExtension =
       this._store.getState().ephemeral.extensions.byId[extensionId]
     if (prevExtension) {
-      if (
-        extension === prevExtension ||
-        shallowEqual(extension, prevExtension)
-      ) {
-        // probably running studio.extend() several times because of hot reload.
-        // as long as it's the same extension, we can safely ignore.
-        return
+      if (reconfigure) {
+      } else {
+        if (
+          extension === prevExtension ||
+          shallowEqual(extension, prevExtension)
+        ) {
+          // probably running studio.extend() several times because of hot reload.
+          // as long as it's the same extension, we can safely ignore.
+          return
+        }
+        throw new Error(
+          `Extension id "${extension.id}" is already defined. If you mean to re-configure the extension, do it like this: studio.extend(extension, {__experimental_reconfigure: true})})`,
+        )
       }
-      throw new Error(`Extension id "${extension.id}" is already defined`)
     }
 
     this.transaction(({drafts}) => {
@@ -296,6 +305,14 @@ export class Studio {
 
       const allPaneClasses = drafts.ephemeral.extensions.paneClasses
 
+      if (reconfigure && prevExtension) {
+        // remove all pane classes that were set by the previous version of the extension
+        prevExtension.panes?.forEach((classDefinition) => {
+          delete allPaneClasses[classDefinition.class]
+        })
+      }
+
+      // if the extension defines pane classes, add them to the list of all pane classes
       extension.panes?.forEach((classDefinition) => {
         if (typeof classDefinition.class !== 'string') {
           throw new Error(`pane.class must be a string`)
@@ -309,9 +326,16 @@ export class Studio {
 
         const existing = allPaneClasses[classDefinition.class]
         if (existing) {
-          throw new Error(
-            `Pane class "${classDefinition.class}" already exists and is supplied by extension ${existing}`,
-          )
+          if (reconfigure && existing.extensionId === extension.id) {
+            // well this should never happen because we already deleted the pane class above
+            console.warn(
+              `Pane class "${classDefinition.class}" already exists. This is a bug in Theatre.js. Please report it at https://github.com/theatre-js/theatre/issues/new`,
+            )
+          } else {
+            throw new Error(
+              `Pane class "${classDefinition.class}" already exists and is supplied by extension ${existing}`,
+            )
+          }
         }
 
         allPaneClasses[classDefinition.class] = {
diff --git a/theatre/studio/src/UI/UI.ts b/theatre/studio/src/UI/UI.ts
index b7d9704..4ecd79d 100644
--- a/theatre/studio/src/UI/UI.ts
+++ b/theatre/studio/src/UI/UI.ts
@@ -24,9 +24,14 @@ export default class UI {
     }
     this._rendered = true
 
-    this._nonSSRBits.then((b) => {
-      b.render()
-    })
+    this._nonSSRBits
+      .then((b) => {
+        b.render()
+      })
+      .catch((err) => {
+        console.error(err)
+        throw err
+      })
   }
 
   hide() {
@@ -53,10 +58,14 @@ export default class UI {
 
     let unmount: null | (() => void) = null
 
-    this._nonSSRBits.then((nonSSRBits) => {
-      if (shouldUnmount) return // unmount requested before the toolset is mounted, so, abort
-      unmount = nonSSRBits.renderToolset(toolsetId, htmlNode)
-    })
+    this._nonSSRBits
+      .then((nonSSRBits) => {
+        if (shouldUnmount) return // unmount requested before the toolset is mounted, so, abort
+        unmount = nonSSRBits.renderToolset(toolsetId, htmlNode)
+      })
+      .catch((err) => {
+        console.error(err)
+      })
 
     return () => {
       if (unmount) {