Well done, Adam.
For me, the most important feature for a short line transition move from upswing to downswing is continued lower body/ski resistance of the load through initiation of that move. So, if you’re still looking for input/edits, please consider deleting the reference to “standing up” (or clarify) as a method of initiating the transition from downswing to strong upswing. That descriptor may confuse some ballers who will focus solely on the phrase and will literally “stand up” as the force coming through the ski is peaking around centerline. Put another way, they will allow the upper body to be pulled forward, up and out of the lean to initiate the transition. I’m pretty sure this is not what you meant.
In giving up lower body resistance, at this key moment when the load coming through the ski is peaking, the skier loses the opportunity to harness that energy for the upswing. Even if the skier resists with the upper body and maintains a good connection to the boat on the upswing thereafter, he has already missed the opportunity to harness a good chunk of the energy generated on the downswing and will end up getting dragged narrow and slow to the ball. I know you would agree that harnessing that energy, not giving it up, as the skier initiates the transition move or through initiation of that move -- is key to success at the shorter line lengths. So, to be specific, please consider these changes to your excellent piece here:
Drop or clarify the “stand up” description.
Consider describing transition techniques, collectively, as "Transition Moves".
Re-emphasize the importance of resisting the load through the ski “as the skier initiates The Transition Move” or “through initiation of The Transition Move”.
Hope this helps.