diff --git a/.gitignore b/.gitignore
index 52f31cf6..956c3b23 100644
--- a/.gitignore
+++ b/.gitignore
@@ -129,3 +129,6 @@ docker-compose.dev.yml
 
 # New layout development files
 new-layouts/
+
+# Generated CRM/accounting documents (runtime) — never commit
+backend/storage/business-docs/
diff --git a/backend/src/routes/adminExpenses.js b/backend/src/routes/adminExpenses.js
index a79923f5..4ef9eb1b 100644
--- a/backend/src/routes/adminExpenses.js
+++ b/backend/src/routes/adminExpenses.js
@@ -48,19 +48,11 @@ function diskUpload(subdir) {
 const inboundUpload = diskUpload('inbound');
 const proofUpload = diskUpload('expenses/proof');
 
-function requireFlag(key, code) {
-  return async (req, res, next) => {
-    try {
-      const row = await db('feature_flags').where({ key }).first();
-      const enabled = row && (row.value === true || row.value === 1 || row.value === '1');
-      if (!enabled) return res.status(403).json({ error: `${key} feature is disabled`, code });
-      return next();
-    } catch (err) { return next(err); }
-  };
-}
-const requireIncoming = requireFlag('incomingInvoices', 'INCOMING_INVOICES_DISABLED');
-const requireExpenses = requireFlag('expenses', 'EXPENSES_DISABLED');
-const requireAccounting = requireFlag('accounting', 'ACCOUNTING_DISABLED');
+// Shared cached feature gate (PR #622 nit 2) — replaces the former local copy.
+const { requireFeatureFlag } = require('../middleware/requireFeatureFlag');
+const requireIncoming = requireFeatureFlag('incomingInvoices', 'INCOMING_INVOICES_DISABLED');
+const requireExpenses = requireFeatureFlag('expenses', 'EXPENSES_DISABLED');
+const requireAccounting = requireFeatureFlag('accounting', 'ACCOUNTING_DISABLED');
 
 router.use(adminAuth);
 
diff --git a/backend/src/routes/adminLedger.js b/backend/src/routes/adminLedger.js
index fdd8cc83..3a948edb 100644
--- a/backend/src/routes/adminLedger.js
+++ b/backend/src/routes/adminLedger.js
@@ -21,17 +21,9 @@ const ledgerService = require('../services/ledgerService');
 const router = express.Router();
 const toInt = (v) => { const n = parseInt(v, 10); return Number.isFinite(n) ? n : undefined; };
 
-function requireFlag(key, code) {
-  return async (req, res, next) => {
-    try {
-      const row = await db('feature_flags').where({ key }).first();
-      const enabled = row && (row.value === true || row.value === 1 || row.value === '1');
-      if (!enabled) return res.status(403).json({ error: `${key} feature is disabled`, code });
-      return next();
-    } catch (err) { return next(err); }
-  };
-}
-const requireAccounting = requireFlag('accounting', 'ACCOUNTING_DISABLED');
+// Shared cached feature gate (PR #622 nit 2) — replaces the former local copy.
+const { requireFeatureFlag } = require('../middleware/requireFeatureFlag');
+const requireAccounting = requireFeatureFlag('accounting', 'ACCOUNTING_DISABLED');
 
 router.use(adminAuth);
 router.use(requireAccounting);
diff --git a/backend/src/services/emailIntakeService.js b/backend/src/services/emailIntakeService.js
index 2a3bd3ff..e96bff60 100644
--- a/backend/src/services/emailIntakeService.js
+++ b/backend/src/services/emailIntakeService.js
@@ -202,6 +202,9 @@ async function roundTripTest({ timeoutMs = 30000, intervalMs = 3000 } = {}) {
   const client = makeImapClient(cfg);
   await connectWithTimeout(client);
   const started = Date.now();
+  // Backoff (PR #622 nit 4): some IMAP servers throttle frequent SELECT/SEARCH.
+  // Grow the gap ×1.5 (cap 8s) so a 30s test does ~5 polls, not ~10.
+  let delay = intervalMs;
   try {
     // eslint-disable-next-line no-constant-condition
     while (true) {
@@ -219,7 +222,8 @@ async function roundTripTest({ timeoutMs = 30000, intervalMs = 3000 } = {}) {
         return { ok: false, sent: true, reason: 'not_received', recipient };
       }
       // eslint-disable-next-line no-await-in-loop
-      await new Promise((r) => setTimeout(r, intervalMs));
+      await new Promise((r) => setTimeout(r, delay));
+      delay = Math.min(Math.round(delay * 1.5), 8000);
     }
   } finally {
     await client.logout().catch(() => {});
diff --git a/backend/storage/business-docs/quote/2026/Q-2026-0001.pdf b/backend/storage/business-docs/quote/2026/Q-2026-0001.pdf
deleted file mode 100644
index 6089659d..00000000
--- a/backend/storage/business-docs/quote/2026/Q-2026-0001.pdf
+++ /dev/null
@@ -1 +0,0 @@
-pdf
\ No newline at end of file