I can't get this to work.
I've set up elevon_output, and verified that the two elevon servos are moving correctly. I've added two more servos for the alternate pair of control surfaces, and attached them to output channels 5 and 6. I've set their rc_functions to differentialSpoiler1 and differentialSpoiler2. However, I cannot get those two servos to move at all, regardless of what I do with my rudder or aileron sticks, in any manual or auto mode.
Am I missing something obvious? I can provide my settings.