I’m testing custom component It stops reading sensor data even if I move it like 1.5-2 meters from the RPi. That is probably caused by interference from other radios.
I am about to play with ESP8266 or Arduino + HM-10 BT module and set up OpenMQTTGateway. I may also go with bt-mqtt-gateway on RPi 1 or RPi Zero that I own. It looks promising and I will definitely need much more range than a few meters
I have also external BT USB dongle from my older RPi, but I’m afraid that it may negatively affect ConBee. That’s why I will probably try to go other solutions that will hopefully work stably as standalone units – “set it and forget it”.