I agree with Dustflyer that you need very little aileron throw, very little. But I disagree with when he said "Your HotSpot shouldn't be doing anything like what you are describing, even if your lateral balance is off". It could still be the lateral balance. If it is way heavy on one side, as you turn into that side and start to pull some elevator to maintain level flight, you start to pull more than 1 G. This makes it roll toward the heavy wing and if you happen to be turning into the heavy wing, the turn will steepen. You may notice this and apply more elevator trying to arrest the descending turn and, of course, now you add more Gs and it rolls more and so on and so on. Soon you are beyond 90 degrees of roll and elevator directly causes you to sink even faster. Check the lateral balance. I am not saying that is definitely it, but its the highest probability I've seen yet (unless you have some really funky mixing going on as Dust suggested).