Filled in your survey, but I doubt my experience will be useful. It's not your typical CAS bust.
We were under radar vectors, looking for an aircraft that made an emergency landing in a field after an engine failure, and did not notice the altitude bust at the time. So we ended up in class A without a formal (SVFR?) clearance, but I suspect that the ATC unit we were talking to, coordinated things with the class A owner anyway.
Only once we had found the aircraft were we kindly asked to descend. Never heard a thing about the bust afterwards.