Feathering - exactly my point - when the day comes you will put the nose down until the point you need to reach stays steady in the windscreen or make a new choice of landing site (or crash site) if that isn't achievable - you won't, I would suggest, be worrying about what speed to fly at because you might fly the perfect range auto as per the RFM and not make the LS!
As far as an academic discussion goes, all PPLs learn advanced autos and are shown the effects of speed changes in auto - why this should be new learning to them now is interesting. Why they need to think about autoing in a 60 plus knot wind is also something of a mystery.