Geistware,

Why do you still want to move the CG aft? If it is for better 3D, you might consider doing this in some sort of "removable" manner so that your plane doesn't require switchable mixing during the flight.

I have all of my rudder mixed out all of the time. But my plane is setup with small throws and a "normal" sequence CG. It is very pure throughout the entire range of attitudes. You probably need a plane with very little mixing to start with.

Ken