I really like it! I’m personally split on adding anything to the Kylo/Vader scene because on one hand I think it’s really powerful to have Kylo be the only speaker so the audience is always wondering what he’s hearing, but on the other it’s a great way to to reinforce his motives like you say.

I’ve thought it would be rather interesting to find lines that Palpatine shares with Snoke and kind of have them bleed into each other every once in a while, since Palpatine is a literal puppeteer for Snoke. Since he’s in such a weak state it would make sense that he can’t maintain the Snoke voice all the time.