I guess the line about “miniaturized Death Star tech” could probably be put back into TLJ.

Rey shouldn’t utter “they were nobody,” allowing Kylo to state the supposed facts. For Rey to say it after searching her feelings confirms it as gospel to the audience. Kylo can just say, “Say it: they were filthy junk traders, who sold off for drinking money. You have no place in this story…”

The Emperor’s laugh can be added as Luke gazes into Kylo’s mind, linking him with his turn to the dark side.

This would probably be too hokey, but you could try adding a distant laugh or something after Snoke is killed. Even if it was done well, it’d pull away from the drama going on.

Some Palpatine-related audio could be added to Rey’s Force vision in TFA. Does he address Rey by name in TROS? If so, add that.