diff --git a/src/main/persistence/migrating-orcad-catalog/orcad-destination-client-state.test.ts b/src/main/persistence/migrating-orcad-catalog/orcad-destination-client-state.test.ts
index 41cc7546184..af30ea3ae3e 100644
--- a/src/main/persistence/migrating-orcad-catalog/orcad-destination-client-state.test.ts
+++ b/src/main/persistence/migrating-orcad-catalog/orcad-destination-client-state.test.ts
@@ -1,5 +1,6 @@
 import { describe, expect, it } from 'vitest'
 import type { PersistedState } from '../../../shared/persisted-state-types'
+import { getDefaultUIState } from '../../../shared/constants'
 import type { OrcadMigrationClientStatePayload } from '../../../shared/orcad-migration/orcad-migration-client-state'
 import {
   applyPreparedOrcadMigrationClientState,
@@ -66,7 +67,7 @@ describe('destination client-state migration', () => {
     expect(destination.ui).toMatchObject({
       lastActiveRepoId: 'repo-1',
       lastActiveWorktreeId: 'repo-1::/worktree',
-      filterRepoIds: ['repo-1'],
+      filterRepoIds: [],
       showDotfilesByWorktree: { 'repo-1::/worktree': false }
     })
   })
@@ -101,11 +102,93 @@ describe('destination client-state migration', () => {
     )
   })
 
-  it('rejects non-default UI routing conflicts', () => {
+  it("moves onto a fresh server whose sidebar shows all hosts, keeping the server's filters", () => {
     const destination = state()
-    destination.ui.lastActiveRepoId = 'other-repo'
-    expect(() => prepareOrcadMigrationClientState(incoming, destination)).toThrow(
-      'orcad_migration_client_state_conflict:ui:lastActiveRepoId'
+    // The server's defaults: 'all' and an all-hosts automation filter, not unset.
+    destination.ui = getDefaultUIState()
+    const prepared = prepareOrcadMigrationClientState(
+      {
+        uiRouting: {
+          workspaceHostScope: 'local',
+          visibleWorkspaceHostIds: ['local'],
+          workspaceHostOrder: ['local'],
+          automationHostFilter: { kind: 'host', hostKey: 'host:runtime:environment-1:self' }
+        }
+      },
+      destination
     )
+    applyPreparedOrcadMigrationClientState(prepared, destination)
+    expect(destination.ui).toMatchObject({
+      workspaceHostScope: 'all',
+      visibleWorkspaceHostIds: null,
+      workspaceHostOrder: [],
+      automationHostFilter: { kind: 'all' }
+    })
+  })
+
+  it("keeps the server's own view preferences instead of refusing the move", () => {
+    const destination = state()
+    destination.ui = {
+      ...destination.ui,
+      lastActiveRepoId: 'server-repo',
+      lastActiveWorktreeId: 'server-repo::/w',
+      filterRepoIds: ['server-repo'],
+      showDotfilesByWorktree: { 'server-repo::/w': true, 'repo-1::/worktree': true },
+      setupScriptPromptDismissedRepoIds: ['server-repo'],
+      manualRepoOrder: [{ hostId: 'local', repoId: 'server-repo' }],
+      workspaceHostScope: 'all',
+      acknowledgedAgentsByPaneKey: { 'server-tab:leaf': 5, 'tab-1:leaf': 9 }
+    }
+    const prepared = prepareOrcadMigrationClientState(
+      {
+        uiRouting: {
+          ...incoming.uiRouting,
+          setupScriptPromptDismissedRepoIds: ['repo-1'],
+          acknowledgedAgentsByPaneKey: { 'tab-1:leaf': 1, 'tab-2:leaf': 2 }
+        }
+      },
+      destination
+    )
+    applyPreparedOrcadMigrationClientState(prepared, destination)
+    expect(destination.ui).toMatchObject({
+      lastActiveRepoId: 'server-repo',
+      lastActiveWorktreeId: 'server-repo::/w',
+      filterRepoIds: ['server-repo'],
+      showDotfilesByWorktree: { 'server-repo::/w': true, 'repo-1::/worktree': true },
+      setupScriptPromptDismissedRepoIds: ['server-repo', 'repo-1'],
+      manualRepoOrder: [{ hostId: 'local', repoId: 'server-repo' }],
+      acknowledgedAgentsByPaneKey: { 'server-tab:leaf': 5, 'tab-1:leaf': 9, 'tab-2:leaf': 2 }
+    })
+  })
+
+  it("ignores an older desktop's host filters on a server already scoped elsewhere", () => {
+    const destination = state()
+    destination.ui = {
+      ...getDefaultUIState(),
+      workspaceHostScope: 'runtime:other',
+      visibleWorkspaceHostIds: ['runtime:other'],
+      workspaceHostOrder: ['runtime:other'],
+      automationHostFilter: { kind: 'host', hostKey: 'host:desktop:self' },
+      filterRepoIds: ['server-repo'],
+      acknowledgedAgentsByPaneKey: { 'tab-1:leaf': 1 }
+    }
+    const before = structuredClone(destination.ui)
+    applyPreparedOrcadMigrationClientState(
+      prepareOrcadMigrationClientState(
+        {
+          uiRouting: {
+            workspaceHostScope: 'local',
+            visibleWorkspaceHostIds: ['local'],
+            workspaceHostOrder: ['local'],
+            automationHostFilter: { kind: 'host', hostKey: 'host:runtime:environment-1:self' },
+            filterRepoIds: ['repo-1'],
+            acknowledgedAgentsByPaneKey: { 'tab-1:leaf': 7 }
+          }
+        },
+        destination
+      ),
+      destination
+    )
+    expect(destination.ui).toEqual({ ...before, acknowledgedAgentsByPaneKey: { 'tab-1:leaf': 7 } })
   })
 })
diff --git a/src/main/persistence/migrating-orcad-catalog/orcad-destination-client-state.ts b/src/main/persistence/migrating-orcad-catalog/orcad-destination-client-state.ts
index 1fdb67f57b7..62b165f7988 100644
--- a/src/main/persistence/migrating-orcad-catalog/orcad-destination-client-state.ts
+++ b/src/main/persistence/migrating-orcad-catalog/orcad-destination-client-state.ts
@@ -1,5 +1,4 @@
 import type { PersistedState } from '../../../shared/persisted-state-types'
-import { hostStableKey, parseHostStableKey } from '../../../shared/automation-owner-key'
 import type {
   OrcadMigrationClientStatePayload,
   OrcadMigrationUiRoutingState
@@ -22,10 +21,7 @@ export function prepareOrcadMigrationClientState(
     incoming?.mobileClientTabSelectionsByDeviceId,
     state
   )
-  const uiRouting = incoming?.uiRouting ? normalizeUiRouting(incoming.uiRouting) : undefined
-  if (uiRouting) {
-    assertUiRoutingCompatible(uiRouting, state)
-  }
+  const uiRouting = incoming?.uiRouting ? structuredClone(incoming.uiRouting) : undefined
   return {
     incoming,
     mobileSelections,
@@ -52,24 +48,6 @@ export function applyPreparedOrcadMigrationClientState(
   }
 }
 
-function normalizeUiRouting(route: OrcadMigrationUiRoutingState): OrcadMigrationUiRoutingState {
-  const filter = route.automationHostFilter
-  if (filter?.kind !== 'host') {
-    return structuredClone(route)
-  }
-  const parsed = parseHostStableKey(filter.hostKey)
-  if (parsed?.authority.kind !== 'runtime' || parsed.selector.kind !== 'self') {
-    return structuredClone(route)
-  }
-  return {
-    ...structuredClone(route),
-    automationHostFilter: {
-      kind: 'host',
-      hostKey: hostStableKey({ authority: { kind: 'desktop' }, selector: { kind: 'self' } })
-    }
-  }
-}
-
 function prepareMobileSelections(
   incoming: OrcadMigrationClientStatePayload['mobileClientTabSelectionsByDeviceId'],
   state: PersistedState
@@ -94,88 +72,76 @@ function prepareMobileSelections(
   return result
 }
 
-// What each routed field reads in this profile, and what it holds when never set.
-const UI_ROUTING_FIELDS: readonly {
-  key: keyof OrcadMigrationUiRoutingState
-  read: (ui: PersistedState['ui']) => unknown
-  empty: unknown
-}[] = [
-  { key: 'lastActiveRepoId', read: (ui) => ui.lastActiveRepoId, empty: null },
-  { key: 'lastActiveWorktreeId', read: (ui) => ui.lastActiveWorktreeId, empty: null },
-  { key: 'filterRepoIds', read: (ui) => ui.filterRepoIds, empty: [] },
-  { key: 'showDotfilesByWorktree', read: (ui) => ui.showDotfilesByWorktree ?? {}, empty: {} },
-  {
-    key: 'setupScriptPromptDismissedRepoIds',
-    read: (ui) => ui.setupScriptPromptDismissedRepoIds ?? [],
-    empty: []
-  },
-  { key: 'manualRepoOrder', read: (ui) => ui.manualRepoOrder ?? [], empty: [] },
-  { key: 'workspaceHostScope', read: (ui) => ui.workspaceHostScope, empty: undefined },
-  { key: 'visibleWorkspaceHostIds', read: (ui) => ui.visibleWorkspaceHostIds, empty: null },
-  { key: 'workspaceHostOrder', read: (ui) => ui.workspaceHostOrder ?? [], empty: [] },
-  { key: 'automationHostFilter', read: (ui) => ui.automationHostFilter, empty: undefined },
-  {
-    key: 'acknowledgedAgentsByPaneKey',
-    read: (ui) => ui.acknowledgedAgentsByPaneKey ?? {},
-    empty: {}
-  }
-]
+type UiRoutingKey = keyof OrcadMigrationUiRoutingState
+type UiRoutingFieldMerge<K extends UiRoutingKey> =
+  /** A filter of one desktop window (its hosts, its repos); the server keeps its own. Ignored here. */
+  | 'desktop-only'
+  /** Folds a moved value into this profile; the server's own value always stands. */
+  | ((ui: PersistedState['ui'], value: NonNullable<OrcadMigrationUiRoutingState[K]>) => void)
 
-function assertUiRoutingCompatible(
-  route: OrcadMigrationUiRoutingState,
-  state: PersistedState
-): void {
-  for (const { key, read, empty } of UI_ROUTING_FIELDS) {
-    const current = serializeOrcadMigrationValue(read(state.ui))
-    if (
-      route[key] !== undefined &&
-      current !== serializeOrcadMigrationValue(route[key]) &&
-      current !== serializeOrcadMigrationValue(empty)
-    ) {
-      throw new Error(`orcad_migration_client_state_conflict:ui:${key}`)
+/**
+ * Every moved sidebar field is per-window view state, so none may refuse a move: what the server
+ * already shows stands, and the desktop's value fills only what the server never set.
+ * Acknowledgements keep the later time. A new field
+ * must pick its merge here; refusals belong to catalog and session identity, never to view state.
+ */
+export const ORCAD_MIGRATION_UI_ROUTING_MERGE: {
+  readonly [K in UiRoutingKey]: UiRoutingFieldMerge<K>
+} = {
+  lastActiveRepoId: (ui, value) => {
+    ui.lastActiveRepoId ??= value
+  },
+  lastActiveWorktreeId: (ui, value) => {
+    ui.lastActiveWorktreeId ??= value
+  },
+  manualRepoOrder: (ui, value) => {
+    if (!ui.manualRepoOrder?.length) {
+      ui.manualRepoOrder = structuredClone(value)
     }
-  }
+  },
+  showDotfilesByWorktree: (ui, value) => {
+    ui.showDotfilesByWorktree = { ...structuredClone(value), ...ui.showDotfilesByWorktree }
+  },
+  acknowledgedAgentsByPaneKey: (ui, value) => {
+    // The later acknowledgement covers the earlier one, so a retry never revives an unread mark.
+    const merged = { ...ui.acknowledgedAgentsByPaneKey }
+    for (const [paneKey, at] of Object.entries(value)) {
+      merged[paneKey] = Math.max(merged[paneKey] ?? 0, at)
+    }
+    ui.acknowledgedAgentsByPaneKey = merged
+  },
+  setupScriptPromptDismissedRepoIds: (ui, value) => {
+    ui.setupScriptPromptDismissedRepoIds = [
+      ...new Set([...(ui.setupScriptPromptDismissedRepoIds ?? []), ...value])
+    ]
+  },
+  filterRepoIds: 'desktop-only',
+  workspaceHostScope: 'desktop-only',
+  visibleWorkspaceHostIds: 'desktop-only',
+  workspaceHostOrder: 'desktop-only',
+  automationHostFilter: 'desktop-only'
+}
+
+const UI_ROUTING_KEYS = Object.keys(ORCAD_MIGRATION_UI_ROUTING_MERGE).filter(isUiRoutingKey)
+
+function isUiRoutingKey(key: string): key is UiRoutingKey {
+  return Object.hasOwn(ORCAD_MIGRATION_UI_ROUTING_MERGE, key)
 }
 
 function applyUiRouting(route: OrcadMigrationUiRoutingState, state: PersistedState): void {
-  const ui = state.ui
-  if (route.lastActiveRepoId !== undefined) {
-    ui.lastActiveRepoId = route.lastActiveRepoId
-  }
-  if (route.lastActiveWorktreeId !== undefined) {
-    ui.lastActiveWorktreeId = route.lastActiveWorktreeId
-  }
-  if (route.filterRepoIds !== undefined) {
-    ui.filterRepoIds = structuredClone(route.filterRepoIds)
-  }
-  if (route.showDotfilesByWorktree !== undefined) {
-    ui.showDotfilesByWorktree = {
-      ...ui.showDotfilesByWorktree,
-      ...structuredClone(route.showDotfilesByWorktree)
-    }
-  }
-  if (route.setupScriptPromptDismissedRepoIds !== undefined) {
-    ui.setupScriptPromptDismissedRepoIds = structuredClone(route.setupScriptPromptDismissedRepoIds)
-  }
-  if (route.manualRepoOrder !== undefined) {
-    ui.manualRepoOrder = structuredClone(route.manualRepoOrder)
-  }
-  if (route.workspaceHostScope !== undefined) {
-    ui.workspaceHostScope = route.workspaceHostScope
-  }
-  if (route.visibleWorkspaceHostIds !== undefined) {
-    ui.visibleWorkspaceHostIds = structuredClone(route.visibleWorkspaceHostIds)
-  }
-  if (route.workspaceHostOrder !== undefined) {
-    ui.workspaceHostOrder = structuredClone(route.workspaceHostOrder)
-  }
-  if (route.automationHostFilter !== undefined) {
-    ui.automationHostFilter = structuredClone(route.automationHostFilter)
-  }
-  if (route.acknowledgedAgentsByPaneKey !== undefined) {
-    ui.acknowledgedAgentsByPaneKey = {
-      ...ui.acknowledgedAgentsByPaneKey,
-      ...structuredClone(route.acknowledgedAgentsByPaneKey)
-    }
+  for (const key of UI_ROUTING_KEYS) {
+    mergeUiRoutingField(key, route, state.ui)
+  }
+}
+
+function mergeUiRoutingField<K extends UiRoutingKey>(
+  key: K,
+  route: OrcadMigrationUiRoutingState,
+  ui: PersistedState['ui']
+): void {
+  const merge = ORCAD_MIGRATION_UI_ROUTING_MERGE[key]
+  const value = route[key]
+  if (merge !== 'desktop-only' && value !== undefined && value !== null) {
+    merge(ui, value)
   }
 }
diff --git a/src/main/persistence/migrating-orcad-catalog/orcad-source-client-state.test.ts b/src/main/persistence/migrating-orcad-catalog/orcad-source-client-state.test.ts
index 601f552a13c..6790c12ba35 100644
--- a/src/main/persistence/migrating-orcad-catalog/orcad-source-client-state.test.ts
+++ b/src/main/persistence/migrating-orcad-catalog/orcad-source-client-state.test.ts
@@ -10,6 +10,7 @@ import {
 } from '../../../shared/client-hosted-browser-page-record'
 import type { WorkspaceSessionState } from '../../../shared/workspace-session-state-types'
 import { collectOrcadMigrationSourceClientState } from './orcad-source-client-state'
+import { ORCAD_MIGRATION_UI_ROUTING_MERGE } from './orcad-destination-client-state'
 
 const source = {
   sshTargetId: 'target-1',
@@ -135,11 +136,34 @@ describe('source client-state migration', () => {
     expect(result.payload?.uiRouting).toMatchObject({
       lastActiveRepoId: 'repo-1',
       lastActiveWorktreeId: 'repo-1::/srv/worktree',
-      workspaceHostScope: 'local',
       showDotfilesByWorktree: { 'repo-1::/srv/worktree': false }
     })
   })
 
+  it("never sends the desktop's sidebar filters, which an older server refuses when they differ", () => {
+    const current = state()
+    current.ui.workspaceHostScope = 'ssh:target-1'
+    current.ui.visibleWorkspaceHostIds = ['ssh:target-1']
+    current.ui.workspaceHostOrder = ['ssh:target-1']
+    current.ui.automationHostFilter = { kind: 'host', hostKey: 'host:desktop:ssh:target-1' }
+    current.ui.filterRepoIds = ['repo-1']
+    current.ui.lastActiveRepoId = 'repo-1'
+
+    const result = collectOrcadMigrationSourceClientState(
+      current,
+      source,
+      catalog,
+      'environment-1',
+      undefined
+    )
+    expect(result.payload?.uiRouting).toEqual({ lastActiveRepoId: 'repo-1' })
+    for (const [key, merge] of Object.entries(ORCAD_MIGRATION_UI_ROUTING_MERGE)) {
+      if (merge === 'desktop-only') {
+        expect(result.payload?.uiRouting).not.toHaveProperty(key)
+      }
+    }
+  })
+
   it('leaves behind a mobile selection that points at a group outside the migrated owner', () => {
     const current = state()
     const sourceOwner = 'ssh:target-1|repo-1::/srv/worktree'
diff --git a/src/main/persistence/migrating-orcad-catalog/orcad-source-client-state.ts b/src/main/persistence/migrating-orcad-catalog/orcad-source-client-state.ts
index d0bcd44d589..92b0dddcbac 100644
--- a/src/main/persistence/migrating-orcad-catalog/orcad-source-client-state.ts
+++ b/src/main/persistence/migrating-orcad-catalog/orcad-source-client-state.ts
@@ -1,5 +1,3 @@
-import { hostStableKey } from '../../../shared/automation-owner-key'
-import { parsePersistedAutomationHostFilter } from '../../../shared/automation-host-filter'
 import type {
   OrcadMigrationClientStatePayload,
   OrcadMigrationUiRoutingState
@@ -42,7 +40,7 @@ export function collectOrcadMigrationSourceClientState(
   const blockedCounts = { 'saved-port-forward': 0 }
   let blockedCount = 0
   const mobile = collectMobileSelections(state, scope, eligibleSession)
-  const uiRouting = collectUiRouting(state, scope, destinationEnvironmentId, eligibleSession)
+  const uiRouting = collectUiRouting(state, scope, eligibleSession)
   const target = state.sshTargets.find((entry) => entry.id === scope.targetId)
   const savedPortForwards = target?.portForwards ? structuredClone(target.portForwards) : undefined
   if (savedPortForwards) {
@@ -119,7 +117,6 @@ function collectMobileSelections(
 function collectUiRouting(
   state: PersistedState,
   scope: ReturnType<typeof createOrcadMigrationSourceScope>,
-  destinationEnvironmentId: string | undefined,
   session: WorkspaceSessionState | undefined
 ): OrcadMigrationUiRoutingState | undefined {
   const ui = state.ui
@@ -130,10 +127,6 @@ function collectUiRouting(
   if (ui.lastActiveWorktreeId && orcadMigrationOwnerMatchesScope(ui.lastActiveWorktreeId, scope)) {
     result.lastActiveWorktreeId = unqualifyOrcadMigrationOwnerKey(ui.lastActiveWorktreeId)
   }
-  const filterRepoIds = ui.filterRepoIds.filter((repoId) => orcadMigrationOwnsRepoId(scope, repoId))
-  if (filterRepoIds.length > 0) {
-    result.filterRepoIds = filterRepoIds
-  }
   const dotfiles = Object.entries(ui.showDotfilesByWorktree ?? {})
     .filter(([ownerKey]) => orcadMigrationOwnerMatchesScope(ownerKey, scope))
     .map(([ownerKey, enabled]) => [unqualifyOrcadMigrationOwnerKey(ownerKey), enabled] as const)
@@ -152,34 +145,7 @@ function collectUiRouting(
   if (manualOrder.length > 0) {
     result.manualRepoOrder = manualOrder
   }
-  if (ui.workspaceHostScope === scope.hostId) {
-    result.workspaceHostScope = 'local'
-  }
-  const visibleHosts = (ui.visibleWorkspaceHostIds ?? []).filter(
-    (hostId) => hostId === scope.hostId
-  )
-  if (visibleHosts.length > 0) {
-    result.visibleWorkspaceHostIds = ['local']
-  }
-  const hostOrder = (ui.workspaceHostOrder ?? []).filter((hostId) => hostId === scope.hostId)
-  if (hostOrder.length > 0) {
-    result.workspaceHostOrder = ['local']
-  }
-  const filter = parsePersistedAutomationHostFilter(ui.automationHostFilter)
-  if (
-    filter.kind === 'host' &&
-    hostStableKey(filter.host) === `host:desktop:ssh:${encodeURIComponent(scope.targetId)}`
-  ) {
-    result.automationHostFilter = destinationEnvironmentId
-      ? {
-          kind: 'host',
-          hostKey: hostStableKey({
-            authority: { kind: 'runtime', environmentId: destinationEnvironmentId },
-            selector: { kind: 'self' }
-          })
-        }
-      : { kind: 'host', hostKey: 'host:desktop:self' }
-  }
+  // Sidebar filters stay behind: they belong to this desktop's window (ORCAD_MIGRATION_UI_ROUTING_MERGE).
   const eligible = session ? collectEligibleSessionIdentity(session, scope) : null
   const sourceTabIds = collectSourceOwnedTabIds(state, scope)
   const acknowledgements = Object.entries(ui.acknowledgedAgentsByPaneKey ?? {}).filter(
diff --git a/tests/e2e/helpers/orcad-upgrade-profile.ts b/tests/e2e/helpers/orcad-upgrade-profile.ts
index 28f9a25bebd..732a62ec671 100644
--- a/tests/e2e/helpers/orcad-upgrade-profile.ts
+++ b/tests/e2e/helpers/orcad-upgrade-profile.ts
@@ -94,6 +94,8 @@ export function seedRelayEraProfile(
     relayPtyId?: string
     /** An unsaved buffer on the editor tab, as hot exit persists it. */
     draftContent?: string
+    /** The sidebar shows only this host, which a server's own all-hosts default once refused. */
+    sidebarScopedToHost?: boolean
   } = {}
 ): RelayEraProfile {
   const now = Date.now()
@@ -280,6 +282,10 @@ export function seedRelayEraProfile(
         lastDetachedAt: now
       })
     }
+    if (options.sidebarScopedToHost) {
+      const ui = state.ui
+      state.ui = { ...(ui && typeof ui === 'object' ? ui : {}), workspaceHostScope: hostId }
+    }
     const partitions = state.workspaceSessionsByHostId
     state.workspaceSessionsByHostId = {
       ...(partitions && typeof partitions === 'object' ? partitions : {}),
diff --git a/tests/e2e/ssh-orcad-shared-login-migration.spec.ts b/tests/e2e/ssh-orcad-shared-login-migration.spec.ts
index f7739636c34..26883ec244c 100644
--- a/tests/e2e/ssh-orcad-shared-login-migration.spec.ts
+++ b/tests/e2e/ssh-orcad-shared-login-migration.spec.ts
@@ -119,10 +119,13 @@ test('a relay-era desktop joins the server another version runs for the same log
     await waitForSessionReady(established.page)
     await desktopB.close(app)
     app = null
-    const seeded = seedRelayEraProfile(desktopB.userDataDir, host.input, {
-      repoPath: host.remoteRepoPath,
-      folderPath: host.remoteFolderPath
-    })
+    // B's sidebar shows only this host; A's server keeps its own all-hosts view.
+    const seeded = seedRelayEraProfile(
+      desktopB.userDataDir,
+      host.input,
+      { repoPath: host.remoteRepoPath, folderPath: host.remoteFolderPath },
+      { sidebarScopedToHost: true }
+    )
     const b = await desktopB.launch()
     app = b.app
     await waitForSessionReady(b.page)