diff --git a/browser_tests/changeTracker.spec.ts b/browser_tests/changeTracker.spec.ts
index 087016d3b0..abaa48f4a7 100644
--- a/browser_tests/changeTracker.spec.ts
+++ b/browser_tests/changeTracker.spec.ts
@@ -3,6 +3,9 @@ import {
   comfyPageFixture as test,
   comfyExpect as expect
 } from './fixtures/ComfyPage'
+import type { useWorkspaceStore } from '../src/stores/workspaceStore'
+
+type WorkspaceStore = ReturnType<typeof useWorkspaceStore>
 
 async function beforeChange(comfyPage: ComfyPage) {
   await comfyPage.page.evaluate(() => {
@@ -19,38 +22,40 @@ test.describe('Change Tracker', () => {
   test.describe('Undo/Redo', () => {
     test.beforeEach(async ({ comfyPage }) => {
       await comfyPage.setSetting('Comfy.UseNewMenu', 'Top')
+      await comfyPage.setupWorkflowsDirectory({})
     })
 
     test('Can undo multiple operations', async ({ comfyPage }) => {
       function isModified() {
         return comfyPage.page.evaluate(async () => {
-          return window['app'].extensionManager.workflow.activeWorkflow
-            .isModified
+          return !!(window['app'].extensionManager as WorkspaceStore).workflow
+            .activeWorkflow?.isModified
         })
       }
 
       function getUndoQueueSize() {
         return comfyPage.page.evaluate(() => {
-          const workflow =
-            window['app'].extensionManager.workflow.activeWorkflow
-          return workflow.changeTracker.undoQueue.length
+          const workflow = (window['app'].extensionManager as WorkspaceStore)
+            .workflow.activeWorkflow
+          return workflow?.changeTracker.undoQueue.length
         })
       }
 
       function getRedoQueueSize() {
         return comfyPage.page.evaluate(() => {
-          const workflow =
-            window['app'].extensionManager.workflow.activeWorkflow
-          return workflow.changeTracker.redoQueue.length
+          const workflow = (window['app'].extensionManager as WorkspaceStore)
+            .workflow.activeWorkflow
+          return workflow?.changeTracker.redoQueue.length
         })
       }
       expect(await getUndoQueueSize()).toBe(0)
       expect(await getRedoQueueSize()).toBe(0)
 
+      // Save, confirm no errors & workflow modified flag removed
       await comfyPage.menu.topbar.saveWorkflow('undo-redo-test')
-      await comfyPage.page.waitForFunction(
-        () => !window['app'].extensionManager.workflow.activeWorkflow.isModified
-      )
+      expect(await comfyPage.getToastErrorCount()).toBe(0)
+      expect(await isModified()).toBe(false)
+
       // TODO(huchenlei): Investigate why saving the workflow is causing the
       // undo queue to be triggered.
       expect(await getUndoQueueSize()).toBe(1)
@@ -75,13 +80,11 @@ test.describe('Change Tracker', () => {
       expect(await getUndoQueueSize()).toBe(2)
       expect(await getRedoQueueSize()).toBe(1)
 
-      // TODO(huchenlei): Following assertion is flaky.
-      // Seems like ctrlZ() is not triggered correctly.
-      // await comfyPage.ctrlZ()
-      // await expect(node).not.toBeCollapsed()
-      // expect(await isModified()).toBe(false)
-      // expect(await getUndoQueueSize()).toBe(1)
-      // expect(await getRedoQueueSize()).toBe(2)
+      await comfyPage.ctrlZ()
+      await expect(node).not.toBeCollapsed()
+      expect(await isModified()).toBe(false)
+      expect(await getUndoQueueSize()).toBe(1)
+      expect(await getRedoQueueSize()).toBe(2)
     })
   })
 
@@ -109,7 +112,7 @@ test.describe('Change Tracker', () => {
     await expect(node).not.toBeCollapsed()
 
     // Run again, but within a change transaction
-    beforeChange(comfyPage)
+    await beforeChange(comfyPage)
 
     await node.click('collapse')
     await comfyPage.ctrlB()
@@ -117,7 +120,7 @@ test.describe('Change Tracker', () => {
     await expect(node).toBeBypassed()
 
     // End transaction
-    afterChange(comfyPage)
+    await afterChange(comfyPage)
 
     // Ensure undo reverts both changes
     await comfyPage.ctrlZ()
@@ -125,7 +128,7 @@ test.describe('Change Tracker', () => {
     await expect(node).not.toBeCollapsed()
   })
 
-  test('Can group multiple transaction calls into a single one', async ({
+  test('Can nest multiple change transactions without adding undo steps', async ({
     comfyPage
   }) => {
     const node = (await comfyPage.getFirstNodeRef())!
diff --git a/browser_tests/copyPaste.spec.ts b/browser_tests/copyPaste.spec.ts
index 50ee5dc7bc..9e9c127c5c 100644
--- a/browser_tests/copyPaste.spec.ts
+++ b/browser_tests/copyPaste.spec.ts
@@ -15,9 +15,9 @@ test.describe('Copy Paste', () => {
     await textBox.click()
     const originalString = await textBox.inputValue()
     await textBox.selectText()
-    await comfyPage.ctrlC()
-    await comfyPage.ctrlV()
-    await comfyPage.ctrlV()
+    await comfyPage.ctrlC(null)
+    await comfyPage.ctrlV(null)
+    await comfyPage.ctrlV(null)
     const resultString = await textBox.inputValue()
     expect(resultString).toBe(originalString + originalString)
   })
@@ -31,7 +31,7 @@ test.describe('Copy Paste', () => {
         y: 643
       }
     })
-    await comfyPage.ctrlC()
+    await comfyPage.ctrlC(null)
     // KSampler's seed
     await comfyPage.canvas.click({
       position: {
@@ -39,7 +39,7 @@ test.describe('Copy Paste', () => {
         y: 281
       }
     })
-    await comfyPage.ctrlV()
+    await comfyPage.ctrlV(null)
     await comfyPage.page.keyboard.press('Enter')
     await expect(comfyPage.canvas).toHaveScreenshot('copied-widget-value.png')
   })
@@ -51,14 +51,14 @@ test.describe('Copy Paste', () => {
     comfyPage
   }) => {
     await comfyPage.clickEmptyLatentNode()
-    await comfyPage.ctrlC()
+    await comfyPage.ctrlC(null)
     const textBox = comfyPage.widgetTextBox
     await textBox.click()
     await textBox.inputValue()
     await textBox.selectText()
-    await comfyPage.ctrlC()
-    await comfyPage.ctrlV()
-    await comfyPage.ctrlV()
+    await comfyPage.ctrlC(null)
+    await comfyPage.ctrlV(null)
+    await comfyPage.ctrlV(null)
     await expect(comfyPage.canvas).toHaveScreenshot(
       'paste-in-text-area-with-node-previously-copied.png'
     )
@@ -69,10 +69,10 @@ test.describe('Copy Paste', () => {
     await textBox.click()
     await textBox.inputValue()
     await textBox.selectText()
-    await comfyPage.ctrlC()
+    await comfyPage.ctrlC(null)
     // Unfocus textbox.
     await comfyPage.page.mouse.click(10, 10)
-    await comfyPage.ctrlV()
+    await comfyPage.ctrlV(null)
     await expect(comfyPage.canvas).toHaveScreenshot('no-node-copied.png')
   })
 
diff --git a/browser_tests/dialog.spec.ts b/browser_tests/dialog.spec.ts
index 7a9dedd446..28f101ede6 100644
--- a/browser_tests/dialog.spec.ts
+++ b/browser_tests/dialog.spec.ts
@@ -36,6 +36,7 @@ test.describe('Execution error', () => {
   }) => {
     await comfyPage.loadWorkflow('execution_error')
     await comfyPage.queueButton.click()
+    await comfyPage.nextFrame()
 
     // Wait for the element with the .comfy-execution-error selector to be visible
     const executionError = comfyPage.page.locator('.comfy-error-report')
diff --git a/browser_tests/extensionAPI.spec.ts b/browser_tests/extensionAPI.spec.ts
index 6114efe2d4..ce075c5ddd 100644
--- a/browser_tests/extensionAPI.spec.ts
+++ b/browser_tests/extensionAPI.spec.ts
@@ -48,7 +48,7 @@ test.describe('Topbar commands', () => {
       })
     })
 
-    const menuItem: Locator = await comfyPage.menu.topbar.getMenuItem('ext')
+    const menuItem = comfyPage.menu.topbar.getMenuItem('ext')
     expect(await menuItem.count()).toBe(0)
   })
 
diff --git a/browser_tests/fixtures/ComfyPage.ts b/browser_tests/fixtures/ComfyPage.ts
index 0df1a6d194..3679ca5bda 100644
--- a/browser_tests/fixtures/ComfyPage.ts
+++ b/browser_tests/fixtures/ComfyPage.ts
@@ -349,6 +349,12 @@ export class ComfyPage {
     await this.nextFrame()
   }
 
+  async getToastErrorCount() {
+    return await this.page
+      .locator('.p-toast-message.p-toast-message-error')
+      .count()
+  }
+
   async getVisibleToastCount() {
     return await this.page.locator('.p-toast:visible').count()
   }
@@ -550,7 +556,7 @@ export class ComfyPage {
   }
 
   async doubleClickCanvas() {
-    await this.page.mouse.dblclick(10, 10)
+    await this.page.mouse.dblclick(10, 10, { delay: 5 })
     await this.nextFrame()
   }
 
@@ -586,43 +592,42 @@ export class ComfyPage {
     await this.nextFrame()
   }
 
-  async ctrlSend(keyToPress: string) {
-    await this.page.keyboard.down('Control')
-    await this.page.keyboard.press(keyToPress)
-    await this.page.keyboard.up('Control')
+  async ctrlSend(keyToPress: string, locator: Locator | null = this.canvas) {
+    const target = locator ?? this.page.keyboard
+    await target.press(`Control+${keyToPress}`)
     await this.nextFrame()
   }
 
-  async ctrlA() {
-    await this.ctrlSend('KeyA')
+  async ctrlA(locator?: Locator | null) {
+    await this.ctrlSend('KeyA', locator)
   }
 
-  async ctrlB() {
-    await this.ctrlSend('KeyB')
+  async ctrlB(locator?: Locator | null) {
+    await this.ctrlSend('KeyB', locator)
   }
 
-  async ctrlC() {
-    await this.ctrlSend('KeyC')
+  async ctrlC(locator?: Locator | null) {
+    await this.ctrlSend('KeyC', locator)
   }
 
-  async ctrlV() {
-    await this.ctrlSend('KeyV')
+  async ctrlV(locator?: Locator | null) {
+    await this.ctrlSend('KeyV', locator)
   }
 
-  async ctrlZ() {
-    await this.ctrlSend('KeyZ')
+  async ctrlZ(locator?: Locator | null) {
+    await this.ctrlSend('KeyZ', locator)
   }
 
-  async ctrlY() {
-    await this.ctrlSend('KeyY')
+  async ctrlY(locator?: Locator | null) {
+    await this.ctrlSend('KeyY', locator)
   }
 
-  async ctrlArrowUp() {
-    await this.ctrlSend('ArrowUp')
+  async ctrlArrowUp(locator?: Locator | null) {
+    await this.ctrlSend('ArrowUp', locator)
   }
 
-  async ctrlArrowDown() {
-    await this.ctrlSend('ArrowDown')
+  async ctrlArrowDown(locator?: Locator | null) {
+    await this.ctrlSend('ArrowDown', locator)
   }
 
   async closeMenu() {
diff --git a/browser_tests/fixtures/components/Topbar.ts b/browser_tests/fixtures/components/Topbar.ts
index bc64fea1d7..b57461e59b 100644
--- a/browser_tests/fixtures/components/Topbar.ts
+++ b/browser_tests/fixtures/components/Topbar.ts
@@ -13,35 +13,46 @@ export class Topbar {
     await this.page.locator('.p-menubar-mobile .p-menubar-button').click()
   }
 
-  async getMenuItem(itemLabel: string): Promise<Locator> {
+  getMenuItem(itemLabel: string): Locator {
     return this.page.locator(`.p-menubar-item-label:text-is("${itemLabel}")`)
   }
 
-  async getWorkflowTab(tabName: string): Promise<Locator> {
+  getWorkflowTab(tabName: string): Locator {
     return this.page
       .locator(`.workflow-tabs .workflow-label:has-text("${tabName}")`)
       .locator('..')
   }
 
   async closeWorkflowTab(tabName: string) {
-    const tab = await this.getWorkflowTab(tabName)
+    const tab = this.getWorkflowTab(tabName)
     await tab.locator('.close-button').click({ force: true })
   }
 
-  async saveWorkflow(workflowName: string) {
-    await this.triggerTopbarCommand(['Workflow', 'Save'])
-    await this.page.locator('.p-dialog-content input').fill(workflowName)
-    await this.page.keyboard.press('Enter')
-    // Wait for the dialog to close.
-    await this.page.waitForTimeout(300)
+  getSaveDialog(): Locator {
+    return this.page.locator('.p-dialog-content input')
   }
 
-  async saveWorkflowAs(workflowName: string) {
-    await this.triggerTopbarCommand(['Workflow', 'Save As'])
-    await this.page.locator('.p-dialog-content input').fill(workflowName)
+  saveWorkflow(workflowName: string): Promise<void> {
+    return this._saveWorkflow(workflowName, 'Save')
+  }
+
+  saveWorkflowAs(workflowName: string): Promise<void> {
+    return this._saveWorkflow(workflowName, 'Save As')
+  }
+
+  async _saveWorkflow(workflowName: string, command: 'Save' | 'Save As') {
+    await this.triggerTopbarCommand(['Workflow', command])
+    await this.getSaveDialog().fill(workflowName)
     await this.page.keyboard.press('Enter')
+
+    // Wait for workflow service to finish saving
+    await this.page.waitForFunction(
+      () => !window['app'].extensionManager.workflow.isBusy,
+      undefined,
+      { timeout: 3000 }
+    )
     // Wait for the dialog to close.
-    await this.page.waitForTimeout(300)
+    await this.getSaveDialog().waitFor({ state: 'hidden', timeout: 500 })
   }
 
   async triggerTopbarCommand(path: string[]) {
diff --git a/browser_tests/interaction.spec.ts b/browser_tests/interaction.spec.ts
index f4cd61bc1a..f4710a99ac 100644
--- a/browser_tests/interaction.spec.ts
+++ b/browser_tests/interaction.spec.ts
@@ -285,7 +285,8 @@ test.describe('Node Interaction', () => {
       position: {
         x: 50,
         y: 10
-      }
+      },
+      delay: 5
     })
     await comfyPage.page.keyboard.type('Hello World')
     await comfyPage.page.keyboard.press('Enter')
@@ -300,7 +301,8 @@ test.describe('Node Interaction', () => {
       position: {
         x: 50,
         y: 50
-      }
+      },
+      delay: 5
     })
     expect(await comfyPage.page.locator('.node-title-editor').count()).toBe(0)
   })
@@ -352,7 +354,8 @@ test.describe('Group Interaction', () => {
       position: {
         x: 50,
         y: 10
-      }
+      },
+      delay: 5
     })
     await comfyPage.page.keyboard.type('Hello World')
     await comfyPage.page.keyboard.press('Enter')
@@ -504,7 +507,7 @@ test.describe('Widget Interaction', () => {
     await expect(textBox).toHaveValue('')
     await textBox.fill('Hello World')
     await expect(textBox).toHaveValue('Hello World')
-    await comfyPage.ctrlZ()
+    await comfyPage.ctrlZ(null)
     await expect(textBox).toHaveValue('')
   })
 
@@ -515,9 +518,9 @@ test.describe('Widget Interaction', () => {
     await textBox.fill('1girl')
     await expect(textBox).toHaveValue('1girl')
     await textBox.selectText()
-    await comfyPage.ctrlArrowUp()
+    await comfyPage.ctrlArrowUp(null)
     await expect(textBox).toHaveValue('(1girl:1.05)')
-    await comfyPage.ctrlZ()
+    await comfyPage.ctrlZ(null)
     await expect(textBox).toHaveValue('1girl')
   })
 })
diff --git a/browser_tests/menu.spec.ts b/browser_tests/menu.spec.ts
index 083a4a4a58..7349df3cd7 100644
--- a/browser_tests/menu.spec.ts
+++ b/browser_tests/menu.spec.ts
@@ -504,6 +504,7 @@ test.describe('Menu', () => {
       await comfyPage.menu.topbar.saveWorkflow(workflowName)
       expect(await comfyPage.menu.topbar.getTabNames()).toEqual([workflowName])
       await comfyPage.menu.topbar.closeWorkflowTab(workflowName)
+      await comfyPage.nextFrame()
       expect(await comfyPage.menu.topbar.getTabNames()).toEqual([
         'Unsaved Workflow'
       ])
@@ -525,8 +526,7 @@ test.describe('Menu', () => {
     })
 
     test('Displays keybinding next to item', async ({ comfyPage }) => {
-      const workflowMenuItem =
-        await comfyPage.menu.topbar.getMenuItem('Workflow')
+      const workflowMenuItem = comfyPage.menu.topbar.getMenuItem('Workflow')
       await workflowMenuItem.click()
       const exportTag = comfyPage.page.locator('.keybinding-tag', {
         hasText: 'Ctrl + s'
diff --git a/browser_tests/nodeSearchBox.spec.ts b/browser_tests/nodeSearchBox.spec.ts
index b3bc562653..426e770cc7 100644
--- a/browser_tests/nodeSearchBox.spec.ts
+++ b/browser_tests/nodeSearchBox.spec.ts
@@ -15,7 +15,7 @@ test.describe('Node search box', () => {
 
   test(`Can trigger on group body double click`, async ({ comfyPage }) => {
     await comfyPage.loadWorkflow('single_group_only')
-    await comfyPage.page.mouse.dblclick(50, 50)
+    await comfyPage.page.mouse.dblclick(50, 50, { delay: 5 })
     await comfyPage.nextFrame()
     await expect(comfyPage.searchBox.input).toHaveCount(1)
   })
diff --git a/src/stores/workflowStore.ts b/src/stores/workflowStore.ts
index b757dd37fc..d9f6aa361a 100644
--- a/src/stores/workflowStore.ts
+++ b/src/stores/workflowStore.ts
@@ -284,32 +284,45 @@ export const useWorkflowStore = defineStore('workflow', () => {
     workflows.value.filter((workflow) => workflow.isModified)
   )
 
+  /** A filesystem operation is currently in progress (e.g. save, rename, delete) */
+  const isBusy = ref<boolean>(false)
+
   const renameWorkflow = async (workflow: ComfyWorkflow, newPath: string) => {
-    // Capture all needed values upfront
-    const oldPath = workflow.path
-    const wasBookmarked = bookmarkStore.isBookmarked(oldPath)
-
-    const openIndex = detachWorkflow(workflow)
-    // Perform the actual rename operation first
+    isBusy.value = true
     try {
-      await workflow.rename(newPath)
-    } finally {
-      attachWorkflow(workflow, openIndex)
-    }
+      // Capture all needed values upfront
+      const oldPath = workflow.path
+      const wasBookmarked = bookmarkStore.isBookmarked(oldPath)
 
-    // Update bookmarks
-    if (wasBookmarked) {
-      bookmarkStore.setBookmarked(oldPath, false)
-      bookmarkStore.setBookmarked(newPath, true)
+      const openIndex = detachWorkflow(workflow)
+      // Perform the actual rename operation first
+      try {
+        await workflow.rename(newPath)
+      } finally {
+        attachWorkflow(workflow, openIndex)
+      }
+
+      // Update bookmarks
+      if (wasBookmarked) {
+        bookmarkStore.setBookmarked(oldPath, false)
+        bookmarkStore.setBookmarked(newPath, true)
+      }
+    } finally {
+      isBusy.value = false
     }
   }
 
   const deleteWorkflow = async (workflow: ComfyWorkflow) => {
-    await workflow.delete()
-    if (bookmarkStore.isBookmarked(workflow.path)) {
-      bookmarkStore.setBookmarked(workflow.path, false)
+    isBusy.value = true
+    try {
+      await workflow.delete()
+      if (bookmarkStore.isBookmarked(workflow.path)) {
+        bookmarkStore.setBookmarked(workflow.path, false)
+      }
+      delete workflowLookup.value[workflow.path]
+    } finally {
+      isBusy.value = false
     }
-    delete workflowLookup.value[workflow.path]
   }
 
   /**
@@ -317,12 +330,17 @@ export const useWorkflowStore = defineStore('workflow', () => {
    * @param workflow The workflow to save.
    */
   const saveWorkflow = async (workflow: ComfyWorkflow) => {
-    // Detach the workflow and re-attach to force refresh the tree objects.
-    const openIndex = detachWorkflow(workflow)
+    isBusy.value = true
     try {
-      await workflow.save()
+      // Detach the workflow and re-attach to force refresh the tree objects.
+      const openIndex = detachWorkflow(workflow)
+      try {
+        await workflow.save()
+      } finally {
+        attachWorkflow(workflow, openIndex)
+      }
     } finally {
-      attachWorkflow(workflow, openIndex)
+      isBusy.value = false
     }
   }
 
@@ -333,6 +351,7 @@ export const useWorkflowStore = defineStore('workflow', () => {
     openedWorkflowIndexShift,
     openWorkflow,
     isOpen,
+    isBusy,
     closeWorkflow,
     createTemporary,
     renameWorkflow,