diff --git a/src/helpers/esp32/MultiTransportCompanionInterface.cpp b/src/helpers/esp32/MultiTransportCompanionInterface.cpp
index d1986f5..89c3cc4 100644
--- a/src/helpers/esp32/MultiTransportCompanionInterface.cpp
+++ b/src/helpers/esp32/MultiTransportCompanionInterface.cpp
@@ -188,6 +188,15 @@ void MultiTransportCompanionInterface::prepareBle(const char* prefix, char* name
 void MultiTransportCompanionInterface::beginBle(const char* prefix, char* name, uint32_t pin_code) {
   prepareBle(prefix, name, pin_code);
   _ble.begin(prefix, name, pin_code);
+  // ATT notification payload is ATT_MTU-3, so SerialBLEInterface::begin()'s
+  // setMTU(MAX_FRAME_SIZE) leaves a full-length frame 3 bytes too big and NimBLE
+  // silently drops the overflow (ble_att_truncate_to_mtu()). MyMesh::queueMessage()
+  // clamps message text to exactly MAX_FRAME_SIZE, so a maximum-length message lost
+  // its last 3 bytes -- over BLE only; USB/TCP/WS were unaffected. Widen it here
+  // rather than in the core: that file is upstream MeshCore, this transport is
+  // vendored in our src/, and setMTU() is a public static, so no core change is
+  // needed. Verified on an M9: the app now negotiates ATT MTU 179 (was 176).
+  NimBLEDevice::setMTU(MAX_FRAME_SIZE + 3);
   _ble_begun = true;
   _ble_enabled = true;
   _ota_ble_released = false;
@@ -228,6 +237,7 @@ void MultiTransportCompanionInterface::enableBle() {
     strncpy(name, _ble_name, sizeof(name) - 1);
     name[sizeof(name) - 1] = '\0';
     _ble.begin(_ble_prefix, name, _ble_pin_code);
+    NimBLEDevice::setMTU(MAX_FRAME_SIZE + 3);   // see beginBle(): ATT payload is MTU-3
     _ble_begun = true;
   }
   _ble_enabled = true;
diff --git a/src/helpers/esp32/WifiRuntimeStore.cpp b/src/helpers/esp32/WifiRuntimeStore.cpp
index 9c32653..67180d4 100644
--- a/src/helpers/esp32/WifiRuntimeStore.cpp
+++ b/src/helpers/esp32/WifiRuntimeStore.cpp
@@ -17,12 +17,6 @@ static const char *WIFI_CONFIG_PWD_KEY = "wifi_pwd";
 static const char *WIFI_CONFIG_RADIO_EN_KEY = "wifi_radio_en";
 static const char *WIFI_CONFIG_WIFI_CHOSEN_KEY = "wifi_chosen";
 static const char *WIFI_CONFIG_BLE_EN_KEY = "ble_en";   // BLE radio on/off (default on)
-static const char *WIFI_CONFIG_PS_KEY = "wifi_ps";      // modem power save once associated
-#if defined(HELTEC_LORA_V4_R8)
-  #define WIFI_CONFIG_PS_DEFAULT 0   // USB-powered Expansion Kit: latency + link stability over mA
-#else
-  #define WIFI_CONFIG_PS_DEFAULT 1   // battery boards keep the DTIM sleep they always had
-#endif
 
 static SdNvsPrefs s_prefs;
 static bool s_begun = false;
@@ -149,20 +143,6 @@ void wifiConfigSetBleEnabled(bool enabled) {
   s_begun = s_prefs.begin(WIFI_CONFIG_NAMESPACE, true);
 }
 
-bool wifiConfigGetPowerSave() {
-  if (!s_begun) wifiConfigBegin();
-  return s_prefs.getUChar(WIFI_CONFIG_PS_KEY, WIFI_CONFIG_PS_DEFAULT) != 0;
-}
-
-void wifiConfigSetPowerSave(bool enabled) {
-  if (!s_begun) wifiConfigBegin();
-  s_prefs.end();
-  if (!s_prefs.begin(WIFI_CONFIG_NAMESPACE, false)) return;
-  s_prefs.putUChar(WIFI_CONFIG_PS_KEY, enabled ? 1 : 0);
-  s_prefs.end();
-  s_begun = s_prefs.begin(WIFI_CONFIG_NAMESPACE, true);
-}
-
 #if defined(TLORA_PAGER)
 void wifiConfigSetPagerWifiBlePhase(PagerWifiBlePhase phase) {
   s_pager_wifi_ble_phase = phase;
diff --git a/src/helpers/esp32/WifiRuntimeStore.h b/src/helpers/esp32/WifiRuntimeStore.h
index cebf6e8..2cf3462 100644
--- a/src/helpers/esp32/WifiRuntimeStore.h
+++ b/src/helpers/esp32/WifiRuntimeStore.h
@@ -27,14 +27,6 @@ void wifiConfigSetRadioEnabled(bool enabled);
 bool wifiConfigGetBleEnabled();
 void wifiConfigSetBleEnabled(bool enabled);
 
-/* Wi-Fi modem power save (DTIM sleep) once associated. ON saves power and gives BLE
- * coexistence airtime; OFF keeps the RX chain up for a lower-latency companion-TCP /
- * web-mirror link and holds a marginal association better. Default ON everywhere
- * except the V4-R8 (USB-powered Expansion Kit form factor; perf pass 2026-08-20).
- * Applied by the main loop after association and live by the Wi-Fi settings toggle. */
-bool wifiConfigGetPowerSave();
-void wifiConfigSetPowerSave(bool enabled);
-
 #if defined(TLORA_PAGER)
 /* Pager coexistence ownership. Wi-Fi intent alone cannot answer whether a
  * cold NimBLE start is safe: touch builds keep the STA scannable even with no
diff --git a/src/main.cpp b/src/main.cpp
index b0fec9f..c203a44 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1691,14 +1691,19 @@ void loop() {
       // BLE coexistence airtime). Deferred to here on purpose: enabling it on the
       // unassociated STA naps the radio through a scan dwell and breaks the setup
       // wizard's WiFi.scanNetworks() ("no networks found"). One-shot.
-      // Persisted preference (Wi-Fi settings -> "Power save"): default ON, except the V4-R8
-      // where it defaults OFF (perf pass 2026-08-20 — lower-latency app link, steadier
-      // association on its weak 2.4 GHz path). The toggle also applies live once associated.
+      //
+      // Unconditional, and deliberately NOT a user preference. This was briefly
+      // configurable (default off on the V4-R8, for a lower-latency app link), but
+      // WIFI_PS_NONE is not a legal sleep mode while the BT controller is running --
+      // modem sleep is exactly what yields airtime to BLE, and the Wi-Fi PM blob
+      // aborts rather than refusing. An R8 with saved credentials and Bluetooth on
+      // crashed on association every time: task "wifi", abort() in pm_set_sleep_type.
+      // The latency it was buying did not exist either: profiling the companion link
+      // showed sync cost is round-trip COUNT (~40 CMD_GET_CHANNEL), with the firmware
+      // accounting for 0.3% of it. So there is nothing to trade away here.
       static bool modem_sleep_set = false;
       if (!modem_sleep_set) {
-        const bool ps = wifiConfigGetPowerSave();
-        WiFi.setSleep(ps);
-        Serial.printf("[wifi] modem power save %s\n", ps ? "on" : "off");
+        WiFi.setSleep(true);
         modem_sleep_set = true;
       }
       if (!sntp_kicked) {
diff --git a/src/ui-touch/UITask.cpp b/src/ui-touch/UITask.cpp
index d35aaaf..e4f1691 100644
--- a/src/ui-touch/UITask.cpp
+++ b/src/ui-touch/UITask.cpp
@@ -14943,18 +14943,6 @@ static void buildMqttSettings() {
 #endif
 }
 
-#if defined(ESP32) && defined(MULTI_TRANSPORT_COMPANION)
-// Wi-Fi modem power save: persist + apply live. Only touches the driver once associated —
-// WiFi.setSleep() on an unassociated STA naps the radio through scan dwells (see main.cpp).
-// esp_wifi_set_ps is a plain setter (no disconnect/begin), so it is safe from the LVGL ctx.
-static void wifiPowerSaveToggleCb(lv_event_t* e) {
-  if (lv_event_get_code(e) != LV_EVENT_VALUE_CHANGED) return;
-  const bool on = lv_obj_has_state(lv_event_get_target(e), LV_STATE_CHECKED);
-  wifiConfigSetPowerSave(on);
-  if (WiFi.status() == WL_CONNECTED) WiFi.setSleep(on);
-}
-#endif
-
 static void buildWifiSettings() {
   lv_obj_t* body = createSettingsModal("", SettingsModalKind::Wifi);   // no group header — the top bar already says "Wi-Fi"
   int y = 0;
@@ -14975,18 +14963,6 @@ static void buildWifiSettings() {
   lv_label_set_text(g_set_modal.wifi_sta_status_l, TR("Loading..."));
   y += SC(30);
 
-  // Modem power save (DTIM sleep) — see wifiPowerSaveToggleCb. Default ON; OFF on the V4-R8.
-  {
-    int rh = settingsRowLabel(body, y, 4, TR("Power save (modem sleep)"), COLOR_TEXT, &g_font_12, 56);
-    lv_obj_t* sw = lv_switch_create(body);
-    lv_obj_align(sw, LV_ALIGN_TOP_RIGHT, 0, y);
-    if (wifiConfigGetPowerSave()) lv_obj_add_state(sw, LV_STATE_CHECKED);
-    lv_obj_add_event_cb(sw, wifiPowerSaveToggleCb, LV_EVENT_VALUE_CHANGED, nullptr);
-    y += LV_MAX(34, rh + 10);
-    y += settingsRowLabel(body, y, 0, TR("Off: snappier app/TCP link, steadier on a weak signal. On: less power, kinder to Bluetooth."),
-                          COLOR_SUB, &g_font_12, 0) + 2;
-  }
-
   // Make sure the network we're currently using shows up as saved, and on first
   // run import any legacy 3-slot profiles into the new known-networks store.
   {