To avoid carpal tunnel issues I try to hover everything but the outer joint/knuckle of my wrist. You have to have some thing to anchor on unless you plan on not moving your fingers otherwise you'll get carpal tunnel from hovering. So, you have to fully commit to arm and wrist-only when full hovering, and I'm guessing if you are full hovering that you must be playing at least like 80cm/360 or slower.
#opinions/consensus on palm and wrist hover
lost mason
You also can't tense your fingers when full hovering, so make sure you get a good relaxed palm grip to avoid CTS (Carpal Tunnel Syndrome).