Ben,
Just came across your question and want to be sure that I understand completely just what you are asking.
Are you only questioning the behavior of the airplane in knife edge flight and/or are you asking about the behavior in inverted flight, or during a complete 360 degree roll?
I have limited experience in any of those categories. Grin.
However, I have a son that is flying the heck out of his Extra 300 and I could use his judgement and info to try and produce an answer to your question.......by being sure just what you are asking!
Regards,
Cap'n Tarmack