Many years ago as a multi instructor I used to do inflight shutdowns at altitude as part of the initial multi endo and I planned the exercise to be within a short distance of an airfield. Beneficial to actually see the feathered prop but more so for showing how to get it started again. (CAO20.6 used to refer to the availability of a shutdown engine for restart. Or some such wording) I did stack the cards in my favor. At a safe alt/airport nearby/100USG is not required for a 1 hour flight/ and 1 of 2 aircraft (Be76) that we used all the time and I knew the charge in the accumulators was good. I would do 1 and only 1 feathered landing as part of an initial multi but with similar personal minimums to mitigate some of the risks. With sound judgement, I believe these things can be done safely but there are limitations on man and machine that must be understood. Mixture cuts at night at low level are just stupid.