In case this helps someone find this:
http://marc.merlins.org/perso/rc/post_2016-08-01_Brotronics-PowerTowerRX-Documentation-for-Pin-Mapping.html
The brotronics LRS receivers are really nice for their find me buzzer and emergency beacon send on FRS channel 1 when signal is lost, and the fact that it’s powered by a backup 1S lipo you can tape directly to the receiver so that it keeps working after you’ve crashed and your main lipo has fallen off. Sadly, their documentation is limited to say the least, so hopefully this helps.