diff --git a/plugins/codex-security/scripts/workbench_validation.py b/plugins/codex-security/scripts/workbench_validation.py
index 7c52f92ed2..a03810d02f 100644
--- a/plugins/codex-security/scripts/workbench_validation.py
+++ b/plugins/codex-security/scripts/workbench_validation.py
@@ -189,8 +189,6 @@ def _valid_measured_scan_usage(usage: object) -> bool:
 def parse_scan_cost(value: str | None) -> str | None:
     if value is None:
         return None
-    if len(value.encode("utf-8")) > 8192:
-        raise SystemExit("Scan cost must be no larger than 8 KiB.")
     try:
         cost = json.loads(value, parse_constant=reject_nonstandard_json_number)
     except (TypeError, UnicodeError, ValueError) as exc:
diff --git a/plugins/codex-security/tests/test_workbench_scan_usage.py b/plugins/codex-security/tests/test_workbench_scan_usage.py
index b8f96436d9..b81a900a68 100644
--- a/plugins/codex-security/tests/test_workbench_scan_usage.py
+++ b/plugins/codex-security/tests/test_workbench_scan_usage.py
@@ -2152,6 +2152,81 @@ def test_completion_uses_latest_account_snapshot_across_owned_sessions(
     )
 
 
+@pytest.mark.parametrize("terminal_status", ["complete", "failed"])
+def test_large_usage_persists_with_terminal_scan_state(
+    tmp_path: Path, terminal_status: str
+) -> None:
+    fixture = _start_scan(tmp_path)
+    usage = {
+        "coverage": "complete",
+        "source": "codex_rollout",
+        "threadCount": 1,
+        **_counts(120, 30, 15),
+        "accountRateLimits": [
+            {
+                "limitId": f"fixture-limit-{index}",
+                "observedAt": fixture.started_at.isoformat(),
+                "primary": {"usedPercent": 6, "windowMinutes": 10080, "resetsAt": 1800000000},
+                "secondary": None,
+            }
+            for index in range(60)
+        ],
+    }
+    cost_json = json.dumps({"usage": usage}, separators=(",", ":"))
+    assert len(cost_json.encode("utf-8")) > 8192
+
+    if terminal_status == "complete":
+        terminal = _complete_scan(fixture, "--cost-json", cost_json)["scan"]
+    else:
+        terminal = fail_scan(
+            fixture.state_dir,
+            fixture.scan_id,
+            "Fixture failure.",
+            "--cost-json",
+            cost_json,
+            environment=fixture.environment,
+        )["scan"]
+
+    assert terminal["progress"]["status"] == terminal_status
+    assert terminal["usage"] == usage
+    stored = scan_command(
+        fixture.state_dir, "get-scan", fixture.scan_id, environment=fixture.environment
+    )["scan"]
+    assert stored["progress"]["status"] == terminal_status
+    assert stored["usage"] == usage
+
+
+def test_completion_collects_large_usage_from_owned_rollouts(tmp_path: Path) -> None:
+    fixture = _start_scan(tmp_path)
+    counted = fixture.started_at + timedelta(microseconds=1)
+    limit_ids = {f"fixture-limit-{index}" for index in range(60)}
+    parent = _rollout(
+        tmp_path,
+        "scan-parent",
+        [
+            _token_event(counted, 120, 15, cached_input_tokens=30),
+            *[_allowance_event(counted, 6, limit_id) for limit_id in sorted(limit_ids)],
+        ],
+    )
+    _state_graph(fixture.environment, {"scan-parent": parent}, [])
+
+    completed = _complete_scan(fixture)["scan"]
+
+    assert completed["progress"]["status"] == "complete"
+    usage = completed["usage"]
+    assert len(json.dumps({"usage": usage}, separators=(",", ":")).encode("utf-8")) > 8192
+    assert usage["coverage"] == "complete"
+    assert usage["threadCount"] == 1
+    assert usage.items() >= _counts(120, 30, 15).items()
+    assert {limit["limitId"] for limit in usage["accountRateLimits"]} == limit_ids
+    assert (
+        scan_command(
+            fixture.state_dir, "get-scan", fixture.scan_id, environment=fixture.environment
+        )["scan"]["usage"]
+        == usage
+    )
+
+
 def test_host_final_usage_saves_allowances_before_token_receipts(tmp_path: Path) -> None:
     fixture = _start_scan(tmp_path)
     arguments = ("--thread-id", "scan-parent", "--turn-id", "turn-scan-parent")