@makerhand,
Found your video to be excellent  
Even though I don't even know what is the problem being solved!
(I'm still on my 12 year old Hitec Optic 6 with a 6-7 year old Frsky module)
Regards

Edit
Occasionally I get RSSI beeps.
Solved so far by
1. Charging Tx lipo if below 11.1v
2. Taping the Rx antennas so that they are at 90degrees to each other.

In case of XM+  receiver (Factory firmware) the RSSI value remain constant, never change depending on distance, you can say RSSI was not working, after updating the firmware it started working as it should be.