My channels are divided:
Throttle
Rudder
2x Elevator
2x Aileron

So that only leaves the one for the choke if I take it off the auto function.
Funny you should mention the dual elevators off one servo and close loop system, I have that on a Weston Hype, pig to install untill you learn the trick of using a small tube from the tail end, but a very slop free way to control two elevator halves.

Mike