Just a suggestion for AI lines in a fanedit, considering the current AI limitations:

Find a useable clip first from SW or another movie with the same actor. One that comes CLOSE to a line you could use with the right emotion and delivery. Then alter a word or two by using the exact same full sentence made with AI (except with a few words changed). Splice the new words into the original line, adjusting pitch slightly by syllable as needed. I’d personally avoid full sentence AI for now. While it does sound like the actor, it sounds like them out of character reading an audiobook out loud. Even if you could load a new sample set of Kylo instead of Adam Driver it would still sound like Kylo casually reading a story. What sounds amazing outside of an edit will sound out of place (or even ridiculous) in an edit.