diff --git a/src/renderer/src/components/sidebar/AddRepoSetupStep.test.ts b/src/renderer/src/components/sidebar/AddRepoSetupStep.test.ts
index 8dc1d16128b..b84b6163c3b 100644
--- a/src/renderer/src/components/sidebar/AddRepoSetupStep.test.ts
+++ b/src/renderer/src/components/sidebar/AddRepoSetupStep.test.ts
@@ -3,7 +3,8 @@ import {
   getInitialProjectAddedChoice,
   getInitialProjectAddedWorktreeName,
   getProjectAddedChoiceOrder,
-  getProjectAddedPrimaryBranchName
+  getProjectAddedPrimaryBranchName,
+  getSyncedProjectAddedChoice
 } from './AddRepoSetupStep'
 
 describe('getInitialProjectAddedWorktreeName', () => {
@@ -19,17 +20,36 @@ describe('getInitialProjectAddedWorktreeName', () => {
 })
 
 describe('getInitialProjectAddedChoice', () => {
-  it('defaults to creating a worktree when Orca found linked worktrees', () => {
-    expect(getInitialProjectAddedChoice(1)).toBe('create')
+  it('defaults to using existing worktrees when Orca found fewer than 10 linked worktrees', () => {
+    expect(getInitialProjectAddedChoice(1)).toBe('existing')
+    expect(getInitialProjectAddedChoice(9)).toBe('existing')
   })
 
   it('defaults to creating a worktree when no linked worktrees were found', () => {
     expect(getInitialProjectAddedChoice(0)).toBe('create')
   })
 
-  it('defaults to creating a worktree when the repo has a named primary branch', () => {
+  it('defaults to creating a worktree when Orca found 10 or more linked worktrees', () => {
+    expect(getInitialProjectAddedChoice(10)).toBe('create')
+    expect(getInitialProjectAddedChoice(11)).toBe('create')
+  })
+
+  it('keeps the discovered-worktree threshold when the repo has a named primary branch', () => {
     expect(getInitialProjectAddedChoice(0, 'main')).toBe('create')
-    expect(getInitialProjectAddedChoice(2, 'main')).toBe('create')
+    expect(getInitialProjectAddedChoice(2, 'main')).toBe('existing')
+    expect(getInitialProjectAddedChoice(10, 'main')).toBe('create')
+  })
+})
+
+describe('getSyncedProjectAddedChoice', () => {
+  it('updates the default choice when worktree detection arrives later', () => {
+    expect(getSyncedProjectAddedChoice('create', false, 2)).toBe('existing')
+    expect(getSyncedProjectAddedChoice('existing', false, 10)).toBe('create')
+  })
+
+  it('preserves a manual selection when worktree detection changes', () => {
+    expect(getSyncedProjectAddedChoice('create', true, 2)).toBe('create')
+    expect(getSyncedProjectAddedChoice('existing', true, 10)).toBe('existing')
   })
 })
 
diff --git a/src/renderer/src/components/sidebar/AddRepoSetupStep.tsx b/src/renderer/src/components/sidebar/AddRepoSetupStep.tsx
index faf911b3fb7..94ae0188ec1 100644
--- a/src/renderer/src/components/sidebar/AddRepoSetupStep.tsx
+++ b/src/renderer/src/components/sidebar/AddRepoSetupStep.tsx
@@ -1,4 +1,4 @@
-import React, { useCallback, useRef, useState } from 'react'
+import React, { useCallback, useEffect, useRef, useState } from 'react'
 import { GitBranch, GitBranchPlus, Settings } from 'lucide-react'
 import { DialogHeader, DialogTitle, DialogDescription } from '@/components/ui/dialog'
 import { Button } from '@/components/ui/button'
@@ -21,6 +21,7 @@ type ProjectAddedContentProps = {
 type SetupStepProps = ProjectAddedContentProps
 
 const DEFAULT_PROJECT_ADDED_WORKTREE_NAME = 'new-workspace-1'
+const EXISTING_WORKTREE_DEFAULT_LIMIT = 10
 
 export function getInitialProjectAddedWorktreeName(
   defaultWorktreeName: string | undefined
@@ -50,12 +51,29 @@ export function getProjectAddedChoiceOrder(
 }
 
 export function getInitialProjectAddedChoice(
-  _hiddenWorktreeCount: number,
+  hiddenWorktreeCount: number,
   _primaryBranchName?: string
 ): ProjectAddedChoice {
+  // Why: a small discovered set is usually worth importing directly; larger
+  // repos are noisy enough that starting fresh should remain the default.
+  if (hiddenWorktreeCount > 0 && hiddenWorktreeCount < EXISTING_WORKTREE_DEFAULT_LIMIT) {
+    return 'existing'
+  }
   return 'create'
 }
 
+export function getSyncedProjectAddedChoice(
+  currentChoice: ProjectAddedChoice,
+  choiceManuallySelected: boolean,
+  hiddenWorktreeCount: number,
+  primaryBranchName?: string
+): ProjectAddedChoice {
+  if (choiceManuallySelected) {
+    return currentChoice
+  }
+  return getInitialProjectAddedChoice(hiddenWorktreeCount, primaryBranchName)
+}
+
 function formatWorktreeCount(count: number): string {
   return `${count} ${count === 1 ? 'worktree' : 'worktrees'}`
 }
@@ -142,6 +160,7 @@ export function ProjectAddedContent({
   const [choice, setChoice] = useState<ProjectAddedChoice>(() =>
     getInitialProjectAddedChoice(hiddenWorktreeCount, primaryBranchName)
   )
+  const [choiceManuallySelected, setChoiceManuallySelected] = useState(false)
   const radioGroupRef = useRef<HTMLDivElement>(null)
   const radioFocusFrameRef = useRef<number | null>(null)
   const trimmedName = worktreeName.trim()
@@ -150,6 +169,19 @@ export function ProjectAddedContent({
   const choices = getProjectAddedChoiceOrder(hiddenWorktreeCount, normalizedPrimaryBranchName)
   const selectedChoice = choices.includes(choice) ? choice : (choices[0] ?? 'create')
 
+  useEffect(() => {
+    // Why: hidden worktree detection can finish after this step mounts, but
+    // should not override an explicit user choice.
+    setChoice((currentChoice) =>
+      getSyncedProjectAddedChoice(
+        currentChoice,
+        choiceManuallySelected,
+        hiddenWorktreeCount,
+        primaryBranchName
+      )
+    )
+  }, [choiceManuallySelected, hiddenWorktreeCount, primaryBranchName])
+
   const cancelRadioFocusFrame = useCallback((): void => {
     if (radioFocusFrameRef.current === null) {
       return
@@ -172,6 +204,7 @@ export function ProjectAddedContent({
   const cycleChoice = useCallback(() => {
     const index = choices.indexOf(selectedChoice)
     const nextChoice = choices[(index + 1) % choices.length] ?? 'create'
+    setChoiceManuallySelected(true)
     setChoice(nextChoice)
     cancelRadioFocusFrame()
     radioFocusFrameRef.current = requestAnimationFrame(() => {
@@ -182,6 +215,13 @@ export function ProjectAddedContent({
     })
   }, [cancelRadioFocusFrame, choices, selectedChoice])
 
+  const markCreateChoiceSelected = useCallback(() => {
+    // Why: editing the name means the user has committed to the create flow,
+    // even if hidden worktree detection finishes afterward.
+    setChoiceManuallySelected(true)
+    setChoice('create')
+  }, [])
+
   const handlePrimaryAction = (): void => {
     if (selectedChoice === 'primary') {
       onStartPrimaryWorktree()
@@ -216,7 +256,10 @@ export function ProjectAddedContent({
               <StartChoiceCard
                 value="primary"
                 selected={selectedChoice === 'primary'}
-                onSelect={() => setChoice('primary')}
+                onSelect={() => {
+                  setChoiceManuallySelected(true)
+                  setChoice('primary')
+                }}
                 onArrowNav={cycleChoice}
                 icon={<GitBranch className="size-4" />}
                 title={`Start from ${normalizedPrimaryBranchName}`}
@@ -227,7 +270,10 @@ export function ProjectAddedContent({
               <StartChoiceCard
                 value="existing"
                 selected={selectedChoice === 'existing'}
-                onSelect={() => setChoice('existing')}
+                onSelect={() => {
+                  setChoiceManuallySelected(true)
+                  setChoice('existing')
+                }}
                 onArrowNav={cycleChoice}
                 icon={<GitBranch className="size-4" />}
                 title="Use existing worktrees"
@@ -237,7 +283,10 @@ export function ProjectAddedContent({
             <StartChoiceCard
               value="create"
               selected={selectedChoice === 'create'}
-              onSelect={() => setChoice('create')}
+              onSelect={() => {
+                setChoiceManuallySelected(true)
+                setChoice('create')
+              }}
               onArrowNav={cycleChoice}
               icon={<GitBranchPlus className="size-4" />}
               title="Create a new worktree"
@@ -257,7 +306,11 @@ export function ProjectAddedContent({
             <Input
               id="project-added-worktree-name"
               value={worktreeName}
-              onChange={(event) => setWorktreeName(event.target.value)}
+              onFocus={markCreateChoiceSelected}
+              onChange={(event) => {
+                markCreateChoiceSelected()
+                setWorktreeName(event.target.value)
+              }}
               placeholder="new-workspace"
               className="h-9"
             />