I have a stack of the cheap Xiaomi Mi Home Temperature & Humidity Monitor Bluetooth Low Energy sensors I purchased from PBTech (Ali has them too for even cheaper) and have been running the PVVX custom firmware on them for the last few years. I recently noticed that PVVX has added support for BTHome V2 which is an open standard format rather than the ATC or PVVX beacon advertising formats.

Also just seen that OpenMQTTGateway has just added support for encrypted BTHome too, so now I can have the sensors setup around my home, broadcasting using encrypted BTHome V2 BLE messages and being picked up by a super cheap ESP32 and then sending the data to Home Assistant or OpenHAB if that is your thing as both are supported in OpenMQTTGateway.

Once the sensors are correctly configured using the PVVX flashing tool in browser. The entities just automagically turn up in Home Assistant without any further intervention.