Ch. 6 = Flaps
Ch. 8 = Modes, Safe/AS3X/Manual (no AS3X)
I suggest using manual mode as one aileron is on channel 5 so SAFE & AS3X does not control it.
I was playing around with greater aileron movement which did slow it down further but it got really prone to stalling with any slow speed turns. I've actually done the flaperon mod on my real AeroScout but was able to program in full aileron movement when the flaps were down. So far I haven't been able to get them to go above center when the flaps are deployed so roll control is low when the flaps are down in the sim.