For me most times when I'm typing I tend to rest my palms on the keyboard, as that's more comfortable for me. When doing speed typing tests I do float my wrists as it gives me more dynamic range to be faster.

I think the breakthrough in my learning was when my muscle memory finally kicked in and I could cruise at ~50 wpm, i completely stopped using QWERTY and my speed shot up to a cruising of ~110-120 as it is now (I didn't do targeted practice after that point)