Yeah, I think in the story of Ascendant, Kylo has a clearer idea of the spirit transfer angle than Rey. In the theatrical, yeah, Rey should say, “But you’ll just overwrite me.” Here she may plausibly believe that stepping onto the dreaded Sith throne may be the only way to take control.
It’s not great, but I think we’re already a good step in a better direction from the theatrical, thanks to RogueLeader.