Yeah, I think any longer lines would seem odd. While “I’ll always be with you!” is a nice sentiment in the novel, it’d seem super, super shoehorned-in in the movie, especially since Rey doesn’t have any kind of facial reaction we could use for that. His ghost appearing shows us the same thing in a much smoother way.

My vote would be for stuff like “Rey!” or similar when they meet up. Then again, she does already know he’s there because she sent the lightsaber to him, so perhaps a “Thanks.”/“Thank you.” (both thanks for the saber teleport, and thanks for healing him and reminding him he’s not doomed to be evil) would work. It’d have to fit with the cheeky, Han Solo-esque body language that Adam Driver adopts once Ben gets his mojo back, so I’d personally lean into swashbuckling and glad to be there to help, rather than going too moody.

While I like the idea of better communicating to the audience that Ben is making a conscious decision to sacrifice himself to save Rey after he crawls out of the pit (as opposed to his death seeming like a surprise in the theatrical), I’m not sure any additional dialogue wouldn’t feel out of place in that scene. It’d have to be something very finely honed and thought through (so not NO, NO, NOOOO!).