Here is the implementation for tests purposes:
https://github.com/1technophile/OpenMQTTGateway/tree/BLEConnect
Now during the scan OMG store the different models of devices, after the scan if we have found a LYWSD03MMC we connect to it and retrieve the data. The time between each connect is BLEinterval
This implementation helped me, thanks to @jschaeke and @francisp for the identification and the tests.