@ShaneH I believe this to be false. The handle path as @Than_Bogan has described is set by the rope length. The shorter the rope, the later we are able to cross the buoy line and the smaller window we have to make a turn. The ski rotation must already be happening before buoy line, which in my world should also be done with two hands on the handle. The more the gap between the optimal handle path and the typical "get as early as possible to the buoy" path, the earlier the skier is forced to release the outside hand (or get ripped narrow) and the less the ski can be rotated.
To answer the set up question, every ski is designed differently, so the fin set ups to accomplish this will vary. Shallowing the fin does help to release the tail to smear, skid, rotate, or however you want to describe the notion. Be careful though as there are consequences to every fin change. And while shallowing the fin may help the ski to its desired effect, if the skier is not utilizing the correct techniques, it will lead to poor results. As always, fix your approach/technique before touching your ski.
I'm going to sign off on this topic. Feel free to continue the discussion in a positive manner, but please hold your questions for me until the next chapter of "Ask Rossi" which will come soon.