I agree with Pace - Thats why gliding is an excellent opportunity to learn kinetic energy management, you learn very quickly about how to manage the 'profile'.
My issue with this post was that a student is closing the throttle to perform a glide approach to land, he prefers this, maybe he has speed management issues? has trouble trimming with idle power on at 70 knts? i know i did.
Aside from the shock cooling issue, A student i'm not sure would know what to do if encountering sink on short final, especially with first stage or worse 2nd stage flap deployed, the natural reaction would be to add power and raise the nose, and i can guarantee this won't be a gentle application increasing the likely hood of losing the power right at the point you need it
At my airfield landing short on almost every runway would probably kill you, this may not be the same on some of the larger tarmac airfields in the UK, but I'm sure those drains, gutters or runway edges would bend a nose wheel quite happily.