I'm currently checking the feasability of using Unifi APs as bluetooth bridges. They run several daemons (bleconnd, btservice, blebrd, blebr2d) that expose bluetooth functionality to Unifi Protect. bleconnd exposes port 8383 which is only available on localhost on the AP, but the protocol is based on JSON and not encrypted. So this is easy to use, but requires SSH port forwarding or another daemon on the AP to use it.
If you have UniFi APs and want to give it a try: GitHub - ThyMYthOS/unifi_ble: Use Unifi access points as bluetooth hubs in Home Assistant · GitHub