If the student does not have confidence in the instructor then that sounds like a problem to me, way beyond any issue with any particular individual thing you might want to do with the aircraft. And, an instructor telling the student to ignore something in the POH, whatever it is, doesn't sound too clever either.
(Too high on approach in a 172? In the ones I fly just point the nose straight down and hang it on the flaps, it won't speed up to beyond the flap limiting speed, no worries about out-of-balance flight near the ground. That's if you really want to play silly b****rs of course - a go-around is the more obvious first choice.)