Just a small detail regarding the TIE Fighters; the First Order special force TIEs (like the one Poe and Finn stole in TFA) are supposed to have been upgraded with hyperdrives (explaining why Finn meant to leave the system instead of landing on Jakku). The TIEs that pursue the Millennium Falcon during the lightspeed skipping scene are also Special force TIEs. But since everyone is cutting the lightspeed skipping sequence, I believe the best course of action would be replace Kylo’s TIE on Exegol with either a TIE Advanced (Vader was stationed in the DS II, so why not?) or a Lambda shuttle.

I love that repurposed Stormtrooper footage! Where does the original come from? Battlefront II?

I second the general idea of:

Mustafar space shot
Vader’s helmet / Vision
establishing Fortress Vader panning shot (recoloured/edited)
poppasketti’s TIE flyover shot.
Stormtroopers landing on Mustafar
Kylo slaughters the Cultists
Kylo hears “Find me” coming from the Wayfinder.