This post is in no way intended to call out anyone...just looking for additional insight/increase my knowledge.
@Vat_69 , can you help clarify a couple things:
In your post (item #2), you mention V-mpr. I'm not familiar with that v-speed? Did you mean V-mp (min. power) or is this something different?
Also, you mentioned the J-model in a spin in this accident (#3). It's not clear to me... I read this event to be, essentially what I'm familar with, as a "rudder stall". Did the aircraft actually enter a spin that was just not called out as such in the report or was it something else?
In reading through the accident report, while it mentions an objective of exploring stall characteristics, I didn't see any overt mention of a spin, aside from refrences to the Feb 2014 departure of the C-130J. For this accident, I only saw the event described as a left roll inverted into a dive. I've read a fair number of accident reports and, with spin having very specific aerodynamic meaning, I guess I would expect that to be called out. You mentioned "grandpa's Cessna" and having flown many a Cessna, including Aerobats, they're very stable and require some effort to get them to enter a spin. However, the numerous times I've spun the airplane, I've never come close to having it roll inverted.
In this case, they first completed the sideslip to the right without even encountering a rudder alert but easily encountered it when slipping to the left.
As such, with a steady heading slip, JedisonsDad's description of keeping power in, rolling left and ultimately coming over the top makes sense; sounds very similiar to an engine-out, rudder stall scenario on a small multi-engine (ie. Baron, Apache, etc)? The LM re-enactment sim probably provides this detail but I haven't seen and probably won't see that.
Hopefully all that made sense. Understand if this is not something you can/want to share.