I am trying to setup a Mecury SRS with a Spektrum DX18G2 in my jet that has retracts but no gear doors. I went through the setup and got all of the flight controls assigned and configured (Ailerons,flaps,elevators, rudder, and nose gear). I also assigned channels for the gyro gain (Llv) and gyro flightmodes (3 pos sw). The problem I'm having is trying to get the brakes and retracts assigned. I've got the brakes set to ch10 and the retracts to ch12 on the transmitter but I cannot get it to work. I tried to go through the door sequencer assistant where it asks you to cycle the gear switch, which I did, but after cycling it a couple of times the little circle next to OK does not do anything when I push SET, the whole thing just hangs, I then have to shut it down. When I restart the gear switch is not recognized.
Another question, is there anyway to configure any of the six channels used for gear doors for other use? Because the gyro uses two channels (gain and flightmode sw) I need 13 channels to run 2-ail, 2-flaps, -2-ele, 2-rudder, throttle, gear, brakes, gain, gyro flightmode.
What am I doing wrong?

Thanks for the help!

Tom