diff --git a/doc/plugins/PLUGIN_RUNNER_EXECUTION.md b/doc/plugins/PLUGIN_RUNNER_EXECUTION.md
index 682d1f8138f..d1e567873c8 100644
--- a/doc/plugins/PLUGIN_RUNNER_EXECUTION.md
+++ b/doc/plugins/PLUGIN_RUNNER_EXECUTION.md
@@ -26,6 +26,8 @@ OpenCode and ACPX require the existing qualified provider profiles.
 Workspace-free providers are not supported here. Codex warm retention is opt-in through `warmTaskVersion: 1`; ACPX and OpenCode remain per-turn.
 The plugin owns project workspace preparation. Core does not prepare or reuse
 a Core Git worktree for a task-only environment.
+Selecting a plain task directory does not add redundant default configuration.
+Retaining that directory does not itself change the run configuration.
 For plugin-backed project storage, Core uses the workspace provider contract.
 The storage plugin must also provide the selected execution environment.
 Its declared workspace modes and strategies remain in effect.
diff --git a/server/src/__tests__/heartbeat-execution-configuration.test.ts b/server/src/__tests__/heartbeat-execution-configuration.test.ts
index bbd6d591506..bcfee2323b8 100644
--- a/server/src/__tests__/heartbeat-execution-configuration.test.ts
+++ b/server/src/__tests__/heartbeat-execution-configuration.test.ts
@@ -159,7 +159,7 @@ describePostgres("heartbeat execution configuration through adapter dispatch", (
       config: { sourceWorkspaceConfig: { ...agent.adapterConfig, homeMode: "preconfigured" }, aiBinding: managed
         ? aiRuntimeConnectionBindingSchema.parse(agent.runtimeConfig!.aiConnection) : undefined },
       policy: { trustPreset: { kind: "standard", preset: "standard", boundary: null, sourcePresets: {} },
-        useIsolatedTaskDirectory: false, explicitTaskDirectory: false },
+        useIsolatedTaskDirectory: false, explicitTaskDirectory: false, requestedExecutionWorkspaceMode: "shared_workspace" },
       environment: { selectedEnvironmentId: null, selectedEnvironmentForConfig: null,
         resolvedInstanceSettings: await instanceSettingsService(db).get(), persistedNativeExecutionInput: persisted },
       services: { secretsSvc: secretService(db), companySkills: companySkillService(db), appendRunEvent: vi.fn(), finalizeAiConnectionBusyDeferral: vi.fn() },
@@ -220,7 +220,7 @@ describePostgres("heartbeat execution configuration through adapter dispatch", (
     }
   });
 
-  async function configuration(f: Awaited<ReturnType<typeof seed>>, config: Record<string, unknown>, snapshot: Record<string, unknown> = {}, type = "paperclip_runner") {
+  async function configuration(f: Awaited<ReturnType<typeof seed>>, config: Record<string, unknown>, snapshot: Record<string, unknown> = {}, type = "paperclip_runner", explicitTaskDirectory = false, requestedExecutionWorkspaceMode: HeartbeatExecutionConfigurationInput["policy"]["requestedExecutionWorkspaceMode"] = "shared_workspace") {
     const [agent] = await db.update(agents).set({ adapterType: type, adapterConfig: config }).where(eq(agents.id, f.agentId)).returning();
     const [run] = await db.insert(heartbeatRuns).values({ companyId: f.companyId, agentId: f.agentId, issueId: f.issueId, scopeKind: "issue", status: "running", contextSnapshot: snapshot }).returning();
     const resolvedInstanceSettings = await instanceSettingsService(db).get();
@@ -230,7 +230,7 @@ describePostgres("heartbeat execution configuration through adapter dispatch", (
         acceptedPlanContinuationWake: false, acceptedPlanWakeRoutingDecision: null,
         taskProjectContext: null, routineEnvContext: { routineId: null, env: null, responsibleUserId: null } },
       config: { sourceWorkspaceConfig: config, aiBinding: undefined },
-      policy: { trustPreset: { kind: "standard", preset: "standard", boundary: null, sourcePresets: {} }, useIsolatedTaskDirectory: false, explicitTaskDirectory: false },
+      policy: { trustPreset: { kind: "standard", preset: "standard", boundary: null, sourcePresets: {} }, useIsolatedTaskDirectory: false, explicitTaskDirectory, requestedExecutionWorkspaceMode },
       environment: { selectedEnvironmentId: null, selectedEnvironmentForConfig: null,
         resolvedInstanceSettings, persistedNativeExecutionInput: null },
       services: { secretsSvc: secretService(db), companySkills: companySkillService(db), appendRunEvent: vi.fn(), finalizeAiConnectionBusyDeferral: vi.fn() },
@@ -238,6 +238,28 @@ describePostgres("heartbeat execution configuration through adapter dispatch", (
     }) };
   }
 
+  it("keeps default task-directory configuration stable when the directory is reused", async () => {
+    const f = await seed();
+    const initial = await (await configuration(f, {}, {}, "paperclip_runner", true)).prepare();
+    const reused = await (await configuration(f, {})).prepare();
+    expect(initial.prepared).toBe(true);
+    expect(reused.prepared).toBe(true);
+    if (!initial.prepared || !reused.prepared) throw new Error("Configuration was not prepared");
+    expect(initial.mergedConfig).toEqual(reused.mergedConfig);
+    expect(initial.configSnapshot).toEqual(reused.configSnapshot);
+  });
+
+  it.each([
+    { mode: "shared_workspace" as const, config: { workspaceStrategy: { type: "git_worktree", baseRef: "main" } } },
+    { mode: "agent_default" as const, config: {} },
+  ])("still selects directory transport instead of a $mode strategy", async ({ mode, config }) => {
+    const f = await seed();
+    const prepared = await (await configuration(f, config, {}, "paperclip_runner", true, mode)).prepare();
+    expect(prepared.prepared).toBe(true);
+    if (!prepared.prepared) throw new Error("Configuration was not prepared");
+    expect(prepared.mergedConfig.workspaceStrategy).toEqual({ type: "project_primary" });
+  });
+
   it.each(["fresh", "saved empty"])("prepares a %s native skill selection while another run holds the company cache lock", async kind => {
     const f = await seed();
     const selected = kind === "saved empty" ? await companySkillService(db).createLocalSkill(f.companyId, { name: "Later assignment" }) : null;
diff --git a/server/src/services/heartbeat.ts b/server/src/services/heartbeat.ts
index 99060a28540..e6e41be53f3 100644
--- a/server/src/services/heartbeat.ts
+++ b/server/src/services/heartbeat.ts
@@ -2614,7 +2614,7 @@ export function heartbeatService(
         run, agent,
         task: { issueId, context, responsibleUserId, acceptedPlanContinuationWake, acceptedPlanWakeRoutingDecision, taskProjectContext, routineEnvContext },
         config: { sourceWorkspaceConfig, aiBinding },
-        policy: { trustPreset, useIsolatedTaskDirectory, explicitTaskDirectory },
+        policy: { trustPreset, useIsolatedTaskDirectory, explicitTaskDirectory, requestedExecutionWorkspaceMode },
         environment: { selectedEnvironmentId, selectedEnvironmentForConfig, resolvedInstanceSettings, persistedNativeExecutionInput },
         services: { secretsSvc, companySkills, appendRunEvent, finalizeAiConnectionBusyDeferral },
         onFailureSecretsResolved: (readSecrets) => { readFailureReportSecrets = () => [...readSecrets(), ...identityRedactor.values]; },
diff --git a/server/src/services/heartbeat/execution-configuration.ts b/server/src/services/heartbeat/execution-configuration.ts
index 8597bdbf660..2fb2a0ef832 100644
--- a/server/src/services/heartbeat/execution-configuration.ts
+++ b/server/src/services/heartbeat/execution-configuration.ts
@@ -68,7 +68,7 @@ export interface HeartbeatExecutionConfigurationInput {
     aiBinding: AiConnectionBinding | undefined;
   };
   policy: Pick<HeartbeatWorkspacePreparationInput["policy"],
-    "trustPreset" | "useIsolatedTaskDirectory"> & { explicitTaskDirectory: boolean };
+    "trustPreset" | "useIsolatedTaskDirectory" | "requestedExecutionWorkspaceMode"> & { explicitTaskDirectory: boolean };
   environment: Pick<EnvironmentSelection,
     "selectedEnvironmentId" | "selectedEnvironmentForConfig" | "resolvedInstanceSettings" | "persistedNativeExecutionInput">;
   services: {
@@ -108,14 +108,17 @@ export async function prepareHeartbeatExecutionConfiguration(db: Db, input: Hear
   // preparation step can fail. Subsequent provider/identity values extend it.
   onFailureSecretsResolved(() => []);
   const aiBinding = preconfiguredHome ? undefined : input.config.aiBinding;
-  const { trustPreset, useIsolatedTaskDirectory, explicitTaskDirectory } = input.policy;
+  const { trustPreset, useIsolatedTaskDirectory, explicitTaskDirectory, requestedExecutionWorkspaceMode } = input.policy;
   const { secretsSvc, companySkills, appendRunEvent, finalizeAiConnectionBusyDeferral } = input.services;
   let managedAiRuntime: ManagedAiRuntime | undefined;
+  const forceDirectoryStrategy = useIsolatedTaskDirectory || (explicitTaskDirectory && (
+    requestedExecutionWorkspaceMode === "agent_default" || Object.keys(parseObject(sourceWorkspaceConfig.workspaceStrategy)).length > 0
+  ));
   const mergedConfig = {
     ...sourceWorkspaceConfig,
     // The base below is already task-owned. Keep directory transport while
     // preserving isolated mode and the mandatory sandbox preflight.
-    ...((useIsolatedTaskDirectory || explicitTaskDirectory) ? { workspaceStrategy: { type: "project_primary" } } : {}),
+    ...(forceDirectoryStrategy ? { workspaceStrategy: { type: "project_primary" } } : {}),
   };
   const configSnapshot = buildExecutionWorkspaceConfigSnapshot(
     mergedConfig,