Dave

I do not know if the aircraft in your scenario have Mode C or Mode S transponders. For most USA pilots with transponders they will be Mode C and there is no easy way for a PowerFLARM to just "ignore" a Mode C transponder if that aircraft has a PowerFLARM as well. If the other aircraft has a Mode S transponder and the PowerFLARM is correctly configured in that aircraft to also transmit the aircraft's ICAO ID then the receiving PowerFLARM can see the same ICAO ID in bith trabsmissions and has a chance of de-duplicating the target. How well all this works in practice you can try...

Darryl