As a relatively experienced commercial pilot I am not sure of the relevance of my experience to handling a complete power loss in flight. Paradoxically, a relatively inexperienced FI(H) is probably going to react better than me !!
I have not had to handle such an event in 15k. How many of us have had such an experience. I would suggest very few.
I believe, with near max pitch, the rotor would decay very quickly to a residual value.