I’ve been thinking for weeks that a great final scene would be a redeemed Ben Solo exiling himself on Ach-to. His Tie Fighter burns in the background as he stares out over the sea, then he turns back to see Luke’s ghost, who raises the X-Wing from the water as a token of forgiveness. Iris out on Luke and Ben finally making amends (which was a weird omission for me in the official version). You’d have to cut these beats from the earlier scene with Rey on the island (but I would do that anyway to remove the Palpatine reveal) and Adam Driver would be rotoscoped from the beginning of the Han memory scene.
I think that contradicts the message of TLJ, where you can’t run away from your problems. Instead of exile, a redeemed Ben should travel the galaxy on his own, fighting injustice he comes across and slowly redeeming himself to return to the Jedi and Rey.
I assume you didn’t read the whole thing. He was planning to have the scene end with ghost Luke raising his X-Wing, giving Ben a chance to leave. I personally like the idea, although it seems difficult to rotoscope Ben into those scenes, and cut around Luke’s X-Wing on Exegol.