Some of the guys want to have extreme amounts of mixing where every surface may have it's own channel. This would include each elevator half (2) each aileron (2), each flap (2), each spoiler(2) or more, brakes, separate nose gear steering, retracts, gear doors, speed brakes, exterior lights, parachute deployment, engine start, separate throttles on multi-engines, drogue chutes, cockpit canopy that opens and the list goes on. Some have said that 14 isn't even enough and are talking about co-pilots with a second transmitter for some functions. The scale guys really get into it. Oh yeah, exterior lights too. See what I mean now? and each of those surfaces I mentioned would need to be trimmable/adjustable.