During a torrential downpour I had rain fade for a moment on the 410 with a 6' Sami in Little Rock, Arkansas. It looks like I'll be moving the 410 to my Perfect Ten, or converting the 922 on the Perfect Ten, though. :(
I do that with an analog C Band and MPEG-2. The C Band controls the servo and polarity. Is there any reason you can't ground the servo to both receivers and use a DPDT toggle to switch control of polarity between receivers?