I use to switch back and forth, thumb for everything but hunting. I had to shorten the bow when I went to a wrist strap, and change the peep height. It all depends on how you anchor, the length of the release and the length of the loop (if any).

Try not to use your thumb to set off the release. ideally it will be back tension and the trigger will be pretty much at the joint where your thumb touches your hand. Do not use the thumb itself. Either shoot it with BT or alternatly shoot it by pulling with your pinky finger (or other fingers) and pulling the trigger into your hand, I've also seen them successfully show by slowly making a fist.