Last week on a piste run in Chamonix I was passed by a skier in "a sled with a single ski underneath". I had seen him at the top of the run with a jacket that suggested he may have been in a high level french team. Short turns, long turns, all in complete control.
Anyway, as he rapidly overtook me on an albeit smooth but hard snow/icy slope I could not help but observe that his movements, limited as they were, in someway epitomised the essence of PMTS type skiing. It was all about tipping and release. It was incredibly impressive. No opportunity to apply much rotation.
There was an NZ skier who won a medal in the last "disabled olympic games" who demonstrated similar attributes - aim for the tipping/angles and the rest will follow.
For me, these have been lessons in observation.