Making the wing, not move around does help with the pitch sensitivity. In an earlier post, I told of my fix to keep the wing from moving. The bolt that comes with the plane, is not a 1/4-20. I don't know the size, however there is a noticeable difference between the two.
So, it's the snapping out that has me curious, because mine still does it. So I read the instructions, since I never read them while building the plane, ooops
My CG is right at the 6 inch mark. Weight, 5 1/2 pounds. Now mine is heavy, it could be an easy half pound lighter. I did use all high torque high speed metal gear servos and a 6 volt, 1100 mill pack.
Recommended 3D rates: 40 degrees of travel. My low rate is 45 degrees. So YES, this would make the plane snap out. My high rate is 70 degrees.
Most current generation 3D planes that I have flown, will allow for extreme throws without stalling the wing. The Funtana, with its scale type wing, with allot of taper in the leading edge, will not allow it. I noticed the same thing with a couple Giles that I have flown.
IMO the snap is a combo of the wing design and the amount of throw. Is there a fix? No. Just reduce the rate on the elevator, however I am gonna play with spoilerons and flaperons.