Sounds to me like you had to much aileron throw in it. Add your -40%expo and must have been quite a ride. Why don't you go down to 10% and take some throw out of the ailerons and try it over again. You can get away with minimum travel on the ailerons and adjust it later on when you get use to it.

I never ad more than 10% on my planes for quite some time until I really get use to it. You get a plane on a maiden flight with full defection and that much expo, just set the TX down and walk away. I recommend minimum on the aileron and no expo for several flights