Thanks for the feedback
The tug was in sink as opposed to us deliberately descending. By the time I abandoned the launch, the tug was in fact climbing again and was moving up the canopy fairly rapidly (I was probably now in that bit of sink).
There's some good ideas there for exercises I can discuss and maybe practice with an instructor next week, weather permitting. I'll also have a chat about what really is "too high" - although I felt uncomfortably high, I'd already eased the stick forward, taking tension off the rope, and had the descending tug in sight.