Well, this next thing is going to look like S*** by comparison, but I made a proof-of-concept for one of my first ideas on this site: instead of removing Rey Palpatine from tRoS, adding it to tLJ.
https://drive.google.com/file/d/16SWIrS_ZVa8QfJNB0ZzBpP7UacwV9lEG/view?usp=sharing
VERY rough cut, though. I used a lot of dialogue from the audiobook.