I use a 9C and I mix them to the elevator 100%. I use the trainer switch to turn the mix on and off. I only use spoilerons for certain
3D moves so I don't have a flaperon mix. I friend uses a 7C and has his on a switch. Not a mix but a switch to kick both AILEs up. It works but is not near as effective. He also uses the spring loaded trainer switch. If you are going to use this mix that is the safest place to have it IMHO.

David