Interesting thread. When I was instructing I went out one day to do the Forced Approach lesson in a C152. We did a total of six PFL's to a field each starting with me pulling the mixture at 2000 ft AGL. By the end of the lesson the students was doing well and we were both happy. So back to the airport for an uneventfull landing and I am allready thinking about my next student as he does the shutdown check and pulls the mixture control right out of the panel
He did not pull any harder than normal and the mixture went to ICO before the cable failed. In 24 years of flying that was the only time I ever had a mixture control fail. Since then the only time I bring the mixture control to ICO is when the airplane is in its final parking spot.
BTW in Canada a full in flight engine shutdown feather, unfeather and restart is a requirement for the ME rating. Personnally I don't like doing them as I have found aircraft without unfeathering accumulators hard to restart in the air and I don't think the advantages of deliberatly creating an unsafe condition outways the training value