Has anyone considered giving this a shot? https://www.reddit.com/r/StarWars/comments/5s8kjz/rey_sees_darth_vader_in_her_force_vision_how_i/ This would be a perfect addition to te visón scene if you ask me.
Honestly I think this would take away from Kylo’s appearance in the force-back. Also, the main point of this edit is a “gentle restructure” of scenes, not to heavily edit the entire movie. But nice idea none the less.