My hand is on the wheel all the time, but when it makes more aggressive turns, I do take my hand off completely, but both hands up on the wheel, ready to take over anytime. When the turn is complete, my left hand is back at the 7-8 oclock position.
Basically, I don't trust FSD to the point where I let it do aggressive turns with both my hands on my lab. It's a beta code after all. It's good right now, but no way I'm going to trust it 100%.
So far, zero red wheels for months for me, and my overall drive experience is much more relaxing compare to pre-Tesla for long drives.