One major suggestion.
Replace the wreckage of the second Death Star on Kef Bir with… the abandoned Imperial Palace on Coruscant, formerly the Jedi Temple from the prequels. It accomplishes a couple of things, tying into the prequels further and it makes more sense for Palpatine to put his Wayfinder there into his actual headquarters instead of an unfinished trap for the Rebels. The one thing it does take away is the symbolism of the respective grandchildren of Palpatine and Vader being in a place where we saw them interact, as mentioned in the documentary, but I think it’s for the best in favor for what I mentioned. Plus, we’d get to see Coruscant one more time.