Ok that could be interesting. I personally feel it’s unneeded but if people come up with a line I can generate to convey that idea then I will gladly do so.
As someone who’s been championing having a new final line for Ben, I know that in the novelization that Rey and he have a brief interaction as she’s flying away where he says “I will always be with you” and she replies “No one’s ever really gone”, echoing what Luke said to her earlier in the film. I think we could have him say both of these lines or maybe just one or the other to her telepathically (my preference would be the latter line).
Other than that, we could just add a couple of simple sort of lines throughout the last act of the movie after his turn during the fight scenes and stuff. I think a good place to maybe add some of these would be after he crawls out of the pit and right before he resurrects Rey where he’s kind of just looking around and cradling her dead body. I know in MR’s edit, he has him say something like “Dad…” during this moment as he helplessly looks around for guidance. But I think just having him mutter a “No” or “Rey…” during this scene could add wonders into the scene and just make the final moments of arguably one of the best characters in this trilogy be a bit less stoic.
EDIT: Actually, just got another idea as well, echoing the very first words we ever hear Kylo Ren say in this trilogy: “Look how far you’ve come”. It’s just a simple sort of reassurance and while it may be kind of cloying, I feel like it fits with some of the schlocky sort of sincerity and melodrama this series has sometimes. And on another note, it also kind of hearkens back to that moment in TFA when he’s all like “I can teach you the ways of the Force!” in a weird sort of roundabout way.
IDK, I’m just kind of spitballing some stuff here.