I used to enjoy pulling straight up into a puff cloud snap rolling until it fell off into a spin coming down. Not really much point to it but it sure was fun in that little biplane. The Bailey Bitty Bipe was the only one ever made so if anybody knows who owns it now tell him to try it. It took two fingers to do a roll.
As previously stated a snap roll is simply an accelerated stall into a spin maneuver. We taught snap rolls on top of a loop in a Citabria so don't see why a Spitfire would have a problem with it unless it is an engine related gyroscopic problem.