Crossing my fingers for him to make an easy switch to f/t...just remember it's all about the prey being warm & offered the right way: evening, dim light, not too
much motion from the tongs, & make the rat seem to be going past your snake, not directly "at" him, & then when he takes it keep still & don't be a distraction.

Sounds to me like you've been doing pretty well...I know how hard it is NOT to handle a new snake too much. Especially for the younger ones.