ELRS 868MHz + Telemetry 915MHz

I need two communication channels: one for communication with the ground station (sending flight missions) and the second for RC (just in case communication with the ground station breaks down, then I can land the drone in manual mode).

I have Holybro P900 telemetry (902-928 MHz) and ELRS module (868MHz). How bad is the idea of putting these two systems on a drone?

I’m not good at this, but it confuses me that the frequency ranges are very close to each other. I used to use 2.4 for the remote control, but it worked lousy

Interference should be minimal with a clear difference in frequency range.
Or this kind of telemetry data transmission with SBUS function.