New Multiplex will buddy box to any brand
Volfy, re the master Tx preserving mixing. I have not been able to test it myself on the RE but the info now from 2 users is that yes, the Evo as master does as you asked. So you can hook up an absolute basic non-computer Tx as the slave, and the RE's mixing e.g. delta, Vtail etc will be applied to the slave.
Harry