I also have to admit that I generally tend to believe scientific authority on scientific matters, at least in mathematics and natural sciences. Could be a defect of mine.

No implication of fallacious appeal intended. Just a reference to the claim that you didn't literally make.

I also rely on scientific expertise in scientific matters but have a different prediction on what it would take for new information on significant topics to become undisputed. It is possible that we also select scientific authorities in different manner. I tend to actively discount for the contributions of social dominance to scientific authority when I'm selecting expert opinions where there is disagreement.

OTOH, In my reading, Eliezer never argued that there is a clear mathematical flaw in the classical theory of QM. (besides the ugly and ad hoc nature of the state reduction, which still does not make the theory mathematically unsound).

I like the idea of de-emphasising distracting labels such as 'Many Worlds' and just sticking with the math and calling it QM. There are the (Born, etc.) equations behind quantum mechanics with which we can make our predictions and that's that.

I assert that adding a claim such as 'most of the information in the function is removed in way that allows the math to still work' is an objective scientific mistake that is not merely aesthetic. I think you disagree with me there. Similar reasoning would also claim that including a mathematically irrelevant garage dragon in a theory makes it objectively unsound science. Likewise on 'there gazillions of fairies who hack the quantum state constantly to make it follow Born predictions'.