Ultimately the MWI is saying “believe the math - configuration space is physical reality”. So you are on solid ground when you give arguments that are mathemati

Ultimately the MWI is saying “believe the math - configuration space is physical reality”. So you are on solid ground when you give arguments that are mathematical, however the metaphysical stuff about the self is basically talking past the MWI, which specifically does not acknowledge that as valid form of argument. I also agree with the post above that arguments about “branch counting” are bunk because you cannot count in a continuous space (see: banach-tarski and related paradoxes).