Pacific Northwest native carvers, Bill Holm in particular, have discovered that there's a nearly ideal placement
for your hand: At the very edge of the bevel, come off that at 90 degrees with an imaginary line back to the handle.
The intersection is where your index finger should be.
Obviously the tool can cut, no matter where you hold it. Work on a 60' pole for a couple of days.
Strike rate: if you listen to and match your heart rate, you can strike for hours.
Hack away like a madman and you will tire fairly quickly.
Obviously, you're having fun.
I use 3 adzes: Sitka & D adze blades from Kestrel Tool and the bigger 7/75 adze from Stubai.