ch 5 gear is a good on/off switch, I opened the tx case up, and disconnected a redundant pot and ran wires to a proportional knob mounted on the top of the case, this gives me on ch 3 a method of slow turning a servo which I use for a smoke gen in my boat.
Its a great tx, and orange clone rx's for less than a tenner work fine! I extensively use one for rc planes and helis, thats what most of the functions are good for