Update: sadly the skiing I have been doing so far this week has all been with new drivers, so some of the sets were pretty all over the place and I never bothered shortening past 28off. My girlfriend (who drove me though the course for the first time ever/third time ever driving a boat) clearly has a knack for it so I had one set where I could start to really get a feel for the new fin. The other sets were good for seeing how it handled when I was scrambling, haha!
The offside is even better than I originally thought. When skiing well, it just feels so much more natural than what I'm used to. The ski used to have a tendency to over-turn and kill my speed, so then it always felt like I was starting my offside pull from a deficit. That's clearly not a problem now. I'm stubborn, so my skiing can get pretty scrappy from time to time; I got very late during a pass with a strong quartering tailwind and attempted a turn that was very stupid and should've blown the tail...it didn't, and even finished the turn smoothly enough for me to get back to a good position and run the rest of the pass.
The onside is still giving me occasional trouble, but much less now. It seems to reward you when you move your hips up over your feet, and punish you with the super slow turns when you don't. For some reason I don't do that consistently on my onside, and it's something I tend to struggle with at the start of almost every season. I suspect the fin's ability to hold more exaggerates that problem, but on the flip side, rewards with a buttery smooth finish to the turn when I get it right.
That's all for now. I'll try to get my girlfriend back behind the wheel again this weekend and see how it feels at -32 and maybe -35 if things are going well.