Can you clarify what you mean by standard QM? I had taken your usage of "standard QM" to mean, as you used it in context, to be collapse interpretations, but strictly speaking standard QM just concerns itself with quantum systems and is not incompatible with MWI.

Edit: it's too late to alter my original ancestor comment, but I think the way I wrote it may have yielded a misunderstanding. I didn't mean to suggest that MWI has value because it can predict phenomena. I meant to say that it has value because it is a metaphysically cleaner model of reality than the collapse interpretations.

By "standard QM" I mean the "textbook quantum mechanics" which is based in a set of postulates (like for example https://personal.utdallas.edu/~son051000/comp/postulates.pdf) including in some form von Neumann's projection postulate.