Heres what I ran into when setting up my powerbox royal. Using the latest software update for the R3 RX gave 24ch (but only in ext out) in doing that, they reduced the UDI output to 12. So I had to downgrade my rev level back one on the R3 (yes using dual Rx's) which made the UDI output back at 16ch which then let me assign my functions separately in the powerbox rather than letting the powerbox combine multiple surfaces into one chanel (Such as flaps, or dual elevators, ect.)