I really do like the idea of Ben healing Rey and disappearing (sans kiss) before she gets up and takes out Palpatine. There’s a couple problems with it though.

it takes too long. The cuts probably need to happen a lot quicker considering whatever’s happening is presumably happening in front of him. Cuts and framing can stretch out the reality of a sequence quite well and suspend disbelief in a LOT of ways (most horror movies simply wouldn’t function AT ALL if that kind of trickery weren’t available and automatically accepted by most audiences) but the length of time her resurrection takes really pushes it.
Even if you manage to cut down the resurrection length so that it could plausibly happen in front of Palpatine while he’s reveling in adulation and transformation (maybe cutting back and forth between the resurrection and the transformation to show he’s pre-occupied and doesn’t notice what’s happening would help - and would make trimming the length of the resurrection more feasible) once Ben (and Leia) disappear, you almost HAVE to then include both of them in the ghosts behind Rey. That’s a lot of work for a scene everyone seems to be very happy with, not just in the creating ghostly images, but in having to re-time and cut down the screentime the other ghosts currently have now.