I have a whiz bang chicken plucker so it’s a bit different, but it’s ALL about proper temp. Too hot and you rip skin, too cool and you beat up the chicken and feathers don’t come off easy.
145-150 degrees is the sweet spot. But YMMV. I use a turkey fryer, it will overshoot the temp easy so keep a good eye on temp before dunking the birds.
I do 4 at a time on killing in cones (I have a set up) and then shut off the heat once it hits the temp, usually o can dunk and defeather the 4 before temps get too low.