With the removal of the bluetooth tracker in 2022.07, I decided to see what it would take to make a separate bluetooth tracker to run on a Raspberry Pi and send presence to Home Assistant. What I ended up with is:
By default it uses a rest sensor to communicate state, but you can use MQTT instead. If you use MQTT then the system uses MQTT Discovery by default, so you’ll get a HA device along with presence trackers for each of bluetooth devices you are tracking.
There’s a pretty extensive readme to help you get it setup. It works with the depreciated pybluez module, so as long as you don’t upgrade past Python 3.9.x you can still use that. There is also an option to use the more modern Bleak library, but it’s a bit harder to setup (that’s covered in the readme as well).
This doesn’t work with anything that doesn’t advertise it’s presence (so Bluetooth tracking devices), but if someone has one they would like to be able to use, I’d probably be willing to buy one and try and figure it out.