Yeah, like I said, once I put Kylo wandering through the snow at the beginning in, his line ideally won’t come in too soon. He hears a Sithy whisper, and this puts him on edge as he goes deeper.
A hypothetical first-time viewer wouldn’t know it at the time, but I chose “You are unworthy” because it is meant to refer to the idea that Rey is possibly the superior heir to the Sith throne, at least in Palpatine’s mind. I think it’s best to leave it vague so we can keep that.
The thing about the insecurity of Rey being a worthier Sith heir wouldn’t land with either Kylo Ren or the audience given that as far as he and we are concerned, at this point of the story the Emperor just wants to have her killed. The drama is that instead of doing that he’s planning on having her side with him. It is not revealed till later that Palpatine wants her as the heir. Therefore I think leaning into that at this point of the story is a bit premature.
That would be the case in Ascendant, but not here. The only reference to Palpatine wanting Rey dead in this edit will be at the very beginning. And honestly, it’s not like he’s stating that’s the only way it can go down - “[The Final Order] will be yours, if you do as I ask. Kill the girl. End the Jedi. And become what your grandfather Vader could not. You will rule the galaxy as the new Emperor.”
Everything after “if” is only what is possible should he succeed, it’s not necessarily the only way Palpatine meets his goal here. Kylo’s line of “Palpatine wants you dead” will be replaced with “Palpatine wants me to fight you”. We have to imagine that after Kylo asked “Who is she?” Palpatine clarified that he just wants the two of them to fight to the death for the throne. So, yes, he would be aware of what’s really going on in this scene.
I’d be interested in possibly slotting Vader’s voice onto Mustafar. I think it might need to be a little more subtle than that, though.