diff --git a/environments.ini b/environments.ini
index 179992a..ac3c070 100644
--- a/environments.ini
+++ b/environments.ini
@@ -851,7 +851,8 @@ custom_hardware = M5 ATOM Lite
 custom_img = img/boards/m5atom-lite.webp
 
 [env:esp32doitv1-aithinker-r01-sx1278]
-platform = espressif32@6.1.0
+platform = ${com.esp32_platform}
+platform_packages = ${com.esp32_platform_packages}
 board = esp32doit-devkit-v1
 board_build.partitions = min_spiffs.csv
 lib_deps =
@@ -931,7 +932,8 @@ upload_flags =
   --port=8266
 
 [env:esp32dev-rtl_433]
-platform = espressif32@6.1.0
+platform = ${com.esp32_platform}
+platform_packages = ${com.esp32_platform_packages}
 board = esp32dev
 board_build.partitions = min_spiffs.csv
 lib_deps =
@@ -972,7 +974,8 @@ custom_description = Gateway using RTL_433_ESP library, need CC1101
 custom_img = img/boards/esp32dev.jpg
 
 [env:esp32dev-rtl_433-fsk]
-platform = espressif32@6.1.0
+platform = ${com.esp32_platform}
+platform_packages = ${com.esp32_platform_packages}
 board = esp32dev
 board_build.partitions = min_spiffs.csv
 lib_deps =
@@ -1017,7 +1020,8 @@ custom_description = Gateway using RTL_433_ESP library and RadioLib with FSK mod
 custom_img = img/boards/esp32dev.jpg
 
 [env:heltec-rtl_433]
-platform = espressif32@6.1.0
+platform = ${com.esp32_platform}
+platform_packages = ${com.esp32_platform_packages}
 board = heltec_wifi_lora_32_V2
 ; ~/.platformio/packages/framework-arduinoespressif32/variants/.../pins_arduino.h
 board_build.partitions = min_spiffs.csv
@@ -1047,7 +1051,8 @@ custom_hardware = ESP32 HELTEC LORA32 V2
 custom_img = img/boards/heltec-wifi-lora-32.png
 
 [env:heltec-rtl_433-fsk]
-platform = espressif32@6.1.0
+platform = ${com.esp32_platform}
+platform_packages = ${com.esp32_platform_packages}
 board = heltec_wifi_lora_32_V2
 ; ~/.platformio/packages/framework-arduinoespressif32/variants/.../pins_arduino.h
 board_build.partitions = min_spiffs.csv
@@ -1107,7 +1112,8 @@ custom_hardware = ESP32 HELTEC LORA32 V2
 custom_img = img/boards/heltec-wifi-lora-32.png
 
 [env:lilygo-rtl_433]
-platform = espressif32@6.1.0
+platform = ${com.esp32_platform}
+platform_packages = ${com.esp32_platform_packages}
 board = ttgo-lora32-v21
 ; ~/.platformio/packages/framework-arduinoespressif32/variants/.../pins_arduino.h
 board_build.partitions = min_spiffs.csv
@@ -1137,7 +1143,8 @@ custom_hardware = ESP32 LILYGO LoRa32 V2.1
 custom_img = img/boards/lilygo-lora32-v21.jpg
 
 [env:lilygo-rtl_433-fsk]
-platform = espressif32@6.1.0
+platform = ${com.esp32_platform}
+platform_packages = ${com.esp32_platform_packages}
 board = ttgo-lora32-v21
 ; ~/.platformio/packages/framework-arduinoespressif32/variants/.../pins_arduino.h
 board_build.partitions = min_spiffs.csv
@@ -1295,7 +1302,8 @@ custom_hardware = ESP32 LILYGO LoRa32 V2.1
 custom_img = img/boards/lilygo-lora32-v21.jpg
 
 [env:esp32dev-multi_receiver]
-platform = espressif32@6.1.0
+platform = ${com.esp32_platform}
+platform_packages = ${com.esp32_platform_packages}
 board = esp32dev
 board_build.partitions = min_spiffs.csv
 lib_deps =
diff --git a/main/main.cpp b/main/main.cpp
index 9bcb68e..3a40c4b 100644
--- a/main/main.cpp
+++ b/main/main.cpp
@@ -35,6 +35,10 @@
 #include "TheengsCommon.h"
 #include "TheengsUtils.h"
 
+#if defined(CONFIG_IDF_TARGET_ESP32) && !defined(ZgatewayBT) && !defined(USE_BLUFI)
+#  include "esp_bt.h" // esp_bt_mem_release() — BT DRAM reclaim in setup()
+#endif
+
 GatewayState gatewayState = GatewayState::WAITING_ONBOARDING;
 static GatewayState previousGatewayState = gatewayState;
 
@@ -1340,6 +1344,23 @@ void setup() {
   Serial.begin(SERIAL_BAUD);
   Log.begin(LOG_LEVEL, &Serial);
   THEENGS_LOG_NOTICE(F(CR "************* WELCOME TO OpenMQTTGateway **************" CR));
+#if defined(CONFIG_IDF_TARGET_ESP32) && !defined(ZgatewayBT) && !defined(USE_BLUFI)
+  // Reclaim the Bluetooth controller's reserved DRAM on BT-less ESP32 builds.
+  // arduino-esp32 3.x releases only the BLE slice: esp32-hal-bt.c initialises
+  // _classicMemReleased = true whenever CONFIG_BT_CLASSIC_ENABLED is unset,
+  // which is the case for a BLE-only controller build — so its
+  // btMemRelease(BT_MODE_CLASSIC_BT) call short-circuits and ~33 KB of the
+  // 0xdb5c reservation is never returned to the heap. ESP32 has Classic BT
+  // hardware (CONFIG_SOC_BT_CLASSIC_SUPPORTED) and the DRAM is reserved
+  // regardless of the configured controller mode. arduino-esp32 2.x released
+  // the whole BTDM region unconditionally here.
+  // Safe no-op if the core ever releases it correctly, or if BT is later started.
+  {
+    uint32_t heapBeforeBtRelease = ESP.getFreeHeap();
+    esp_bt_mem_release(ESP_BT_MODE_BTDM);
+    THEENGS_LOG_NOTICE(F("BT DRAM reclaimed: %d -> %d" CR), heapBeforeBtRelease, ESP.getFreeHeap());
+  }
+#endif
 #if defined(TRIGGER_GPIO) && !defined(ESPWifiManualSetup)
   pinMode(TRIGGER_GPIO, INPUT_PULLUP);
   checkButton();