^ My read on Luke’s comment about “Leia knew it, too” is that Luke MUST have learned about this only after he had died. Leia must have known, then told Luke, who then displays this knowledge to Rey while saying “Leia knew too.” TLJ Luke just does not seem to be in on this secret. Even so, I don’t see a good way to remove it unless you’re going to go whole hog and remove Rey Palpatine altogether.
I can boost the audio after the chess scene. I assume you mean the, “I’m kidding!” and subsequent bickering? I wanted it to feel like it’s coming from a few rooms away and not that audible, but enough to sell that it was happening onboard while Rey was getting off the ship.