Hi Alec, The critical angle is 16 deg, depending on how Accu-Feel operates you may want to use 15 deg or even a bit lower to get some buffet in the stall on-set phase. As you’ve likely noticed the Bitching Betty alert sounds in that on-set phase. There’s also a very subtle buffet sound effect once the stall is established.
One of the bonuses of working on the RV-7 has been the tremendous amount of detailed and analytical material and discussion. For the most part RV pilots are their own test pilots, so there’s a lot of great specific knowledge out there. I am mindful that some of my questions can’t be answered directly; for instance, stressful or damaging power settings; or, some maximum performance limits. Since the spin is so aggressive I’ve been very reluctant to ask for pilot help. But I think that will happen. Lol, I’ve not yet seen a video with more than a few turns
The nervous laugh at the end of the video speaks volumes. It's likely the nature of the spin is a concession of sorts for the RV’s responsive and nimble control.