If you are considering this from a *smaller* helicopter point of view:
Suppose you have 25-30kts to play with above best autorotative speed, and you were thinking about trading kinetic energy rather than altitude. To have this amount of margin on a small helicopter generally is going to require a particularly high pitch angle; you won't be far off VNE. The question is, with such high pitch angles could the flare effects be sufficient to keep the RRPM in the green if you did nothing to the collective? I envisage the required flare being so aggressive that the speed will have been washed off back to best auto speed in a couple of seconds, thus meaning very little difference from lowering the collective in the first place!
Anyone (deliberately
) not lowered the collective immediately in a small helicopter like the R22 so they could trade kinetic not potential energy?