I am curious to hear your experiences on getting complete or almost complete room coverage for BLE tracking of low-power devices. In particular, I have a Wear OS smart watch and the HA app installed on it. I enabled the BLE transmitter sensor on it and I can successfully track my watch via the Bermuda add-on. However, given its low power nature, the watch emits a relatively weak BLE signal, and my ESP32 nodes hardly pick the watch up unless I bring it rather close to an ESP.
For example, I have two ESP32 D1 mini’s (ESP32-WROOM-32) set up in Bermuda and they are roughly 2.5 meters apart in the same room. Sometimes neither of them picks up presence of the watch when it is half-way between them. I haven’t put either of the ESPs into a case yet, so I assume the signal will get only weaker when I do that. My experience with ESP32 NodeMCUs (ESP32-WROOM-32 too) is similar.
What hardware do you use to track low power BLE devices? Do you use external antennas?
What can I do to improve low-power device tracking if I aim for complete room coverage for every room in my house?
With my Wear OS watch the problem isn’t power so much as the fact that it sleeps a lot of the time. My M5Stack Atoms (two to a room, also Bermuda) pick it up OK, it just isn’t viable as a tracker on it’s own.
An update: I only had to properly configure Bermuda and now it detects the watch as expected. What I forgot to do is to tweak global reference power at the one meter distance. Now detection works much better and reported distance is more realistic. Also, one can tweak per-device reference power once the global reference power is set properly.
How did your identity your watch?
You mean how I got its iBeacon UUID? It’s a guess game. You open up e.g. the Bermuda integration and go to Select devices to start tracking a device. It will list iBeacons it has spotted so far. Hopefully one of them is your watch.
Also, you can use the HA companion app. Go to the sensors you expose from your phone and enable its BLE monitor. Then it will list UUIDs it sees. Walk with your phone and watch on you and the UUID that is consistently in its list of spotted UUIDs must be the one you are looking for.
Yes I thought as much no easy way. I opened up Bermuda and a huge list because my lights and matter devices and google home and computers all have Bluetooth. Thought there might be another way 
Walk with your phone and watch outside away from anything else that might have Bluetooth. Then check your phone BLE monitor in HA.