First of all, what a great project!
Please forgive me if this questions has been asked and allready answered:
As phones are using random BLE beacon MAC addresses it is not ideal to use the default config, as you will get a long list of devices as unique retained topics. I know I can configure it so that it only publishes sensors not beacons (bt_publish_only_sensors), however it would be very nice if it was possible to publis the BT scan result to a separate topic, i.e.: publish this line (from the serial monitor):
"N: Found 17 devices, scan number 1 end deinit controller" " basically a total number of devices found, similar to i.e.: the ttn paxcounter project.