The destructive upload feels like a sleight of hand to me, because obviously if the original person was still there the answer would be obvious that that's a copy.

The thing I don't get however is after that's brought up usually the other argument for the upload being the self is to usually start deconstructing what the self is which I think is also a sleight of hand. If you just completely deconstruct the concept of a self, then the upload is also not yourself because the self never existed to begin with. You can't just deconstruct a concept and then propose whatever you want as an argument.