Have you thought of wiping right to the TIEs/Star destroyer in space establishing shot, then to Vader’s castle, then to the TIE flyby and Battlefront cutscene? It might be the best way to remind the viewer this planet is Mustafar and sneak in the castle. Granted, the current transition is already pretty good.
I may have missed this bit, but how does your restructure justify Ren not wearing the helmet while searching for Exegol?