Step Turn
Delta V, I've posted a comment about shock cooling here: "NJK blew a jug today"
Fair enough but I'd contend there is a world of difference between a PFL as commonly conducted by flight instructors (the ones in my experience anyway) and the business of glider tugging.
On one of my more recent biannual rides I grumbled about this to the instructor and he, in good part, opted for the course of action proposed by BPF;
The good news is you don't have to do PFL's to get good at judging the gliding flight path, you just have to, when practicable, close the throttle on a regular landing at various parts of the circuit.
I was given a particular, quite restricted, section of the runway to arrive on, told that when, at circuit height, I judged I could make that, to close the throttle and to not touch it again until we were on the ground. I didn't miss.
I'd like to make one last observation on all of this and it has to do with how the circuit is flown. I see many fly long final approaches which gives very little latitude for adjustment should the need arise. Tighter, squarer circuits seem to me to be inherently more adjustable to allow for contingencies on the way down. This was clearly illustrated to me some years ago at a
timed-circuit-spot-landing competition at a local field. Those who flew long rectangular circuits may have made the line but never came close to making the time. The squarer circuit could be tightened or relaxed on downwind to hit both time and line targets simultaneously.