How to make sure only one client connect to the BLE server on ESP32?

Question

I'd like to prevent multiple connections to my ESP32.

Is there a built-in way or a better way to do it?

My current implementation is as follows:

static volatile uint16_t connectionIdToKeep = -1;

class ServerCallbacks: public BLEServerCallbacks {
    void onConnect(BLEServer* pServer) {
        ble.log("ServerCallbacks: Connected");
        
        const auto id = pServer->getConnId();

        if (ble.deviceConnected) {
            ble.alert("ServerCallbacks: Client %x is already connected! Disconnecting new one %x", connectionIdToKeep, id);
            pServer->disconnect(id);
            return;
        }

        connectionIdToKeep = id;
        ble.deviceConnected = true;
        ble.lastTimeDeviceConnectedInSeconds = millis()*1e-3;
        
        ble.success("ServerCallbacks: Client %x is connected, welcome!", connectionIdToKeep);

    
        #if SUPPORT_BUZZER
        /// BLE connection jingle
        buzzer.playBleConnectedMelody();
        #endif
    };
 
    void onDisconnect(BLEServer* pServer) {
        const auto id = pServer->getConnId();
        
        /// Should I disconnect silently?
        if (id != connectionIdToKeep) {
            ble.warn("ServerCallbacks: Disconnected unwanted connection %x", id);
            return;
        }
        ble.deviceConnected = false;
        ble.success("ServerCallbacks: Disconnected");

        #if SUPPORT_BUZZER
        /// BLE connection jingle
        buzzer.playBleDisconnectedMelody();
        #endif
        
    }
};