I used a kisser button the first year I learned how to shoot bow and bowhunt. I haven't used one in the 22 years since.
Copper I know little to nothing about using the thumb release. I tried it once and when I drew it felt like I was going to have a seizure. So used to the wrist release (no velcro) that drawing with the t handle it threw me off. I do get the logic with a thumb release and a kisser.