G'day Mate,
Please excuse my stupidity, but what makes everyone believe, that exponential on the elevator is going to fix a plane with too much elevator throw.
EXPO does not reduce the throw, it only makes the stick less sensitive around neutral, the more EXPO used, the further out from the centre the stick is desensitised, but when you get to the end of the EXPO setting, you will get linear movement, & if that is too much & causes a stall, BANG she snaps.
You must reduce your throws, & the easiest way is to reduce your rate settings.
Then fly it & see how it performs.
I would almost guarantee that it is not a dog if flown the way it was designed, I don't believe this particualar plane is designed for 3D.