Add in Palpatine explaining, in complete and thorough detail, the cloning process causing him to return in Rise of Skywalker.
Don’t want the plothole of having to fill it in with your imagination, after all.
Actually, I think making an explanation for Palpatine’s return and the Sith Eternal would make their battle against the Resistance a lot more interesting and believable. Sure, it will never happen due to the Mystery Box rating, but making the stakes of the battle understandable would honestly be an improvement.