Thank you for the suggestion! I’ve considered ending with the Falcon going into hyperspace. But that depends on if and how I fit that sequence into TLJ. I feel like if the arrival on Ahch-To is moved to TLJ I would like that to be the opening sequence, but perhaps it also works if it’s just inserted before the first Ahch-To scenes in TLJ. I haven’t made a final decision on that yet.
I thought about that as well, when I was trying to restructure the opening battle to be the 3rd act in The Force Awakens instead. That battle is really tricky, it both solidifies Poe as being a protagonist in The Force Awakens but it also is the inciting incident for almost all of the characters in The Last Jedi. I eventually landed with leaving it as is, and cutting down some of the jokes in the conversation between Poe and Hux. I also really love that opening shot to The Last Jedi from the stars, past the ships, down to D’Qar, which I don’t really think fits if it’s not the opening. By having Rey’s arrival cut down (I swap from Force Awakens to Last Jedi shots when Rey has her last look at Chewie) it makes the lightsaber moment less of a bait and switch after all of the buildup.
https://drive.google.com/file/d/1rARUzDyLV0hM6eQX4m5U7MkG7AEWxRmU/view?usp=sharing
Your other idea is interesting as well, but I don’t have any detailed ideas for editing TROS yet so I can’t say what I’ll do in that case.
Most of my ideas in Rise of Skywalker are cutting things down and re-arranging sequences to make more sense. Chewie being alive is revealed later, Rey arrives at Exegol while the Resistance is still planning on following her, etc. I cut down the romance with Zorri since she was basically only in the film so Disney could tell Asian markets “No homo!” and made the ending suggest romance between Poe and Finn.
I also put the First Order’s defeat across the galaxy after the heroes’ reunion, leading into a slightly altered version of The Last Jedi’s broom boy ending (so the other boy says “Jedi Skywalker” in his story to refer to Rey who chooses her new name while confronting Palpatine).