Harry what a great post and excellent answer. Tippy top.
I flew B200s in the late 80's and 90's and was lucky enough to amass 5000 hours on them. I never flew one with the Raisbeck mod. We always used or activated the autofeather function I am not sure even if the MEL allowed the aircraft to be dispatched with it U/S. I am pretty sure it was never a issue, because as you said the system is pretty robust.
Even one of the requirements to take advantage of the Take-off minima of ceiling zero feet; and 550m or 800m vis is dependent on operative autofeather, for that safety factor.
The operator on the type I fly now include a check in the emergency recall to confirm autofeather. It should happen....just checking....you never know.....you know!!!! Nothing is full proof in other words.
Simulators are great tools for training on the effects of engine failures etc. I would be nice to see a cost effective generic simulator established that can demonstrate the issues that you described.
Craven.