So the diff preload definitely made a huge difference in the Ferrari. Took it down to 40nm and the car started to rotate in ways I wanted it to. I also started looking at some other setups and people are actually going the other way than I suggested with the Ferrari, tightening up the front and loosening up the back. I tried that and that felt better as well. So I think I'm starting to come to grips with a decent baseline setup for the Ferrari that works for me.