A wavefunction may evolve over time, but configuration space does not.
This is probably not true. To really get off the ground with quantum field theory, you have to attach an a priori different Hilbert space of states to each space-like slice of spacetime, and make sense of what equations of motion could mean in this setting--at least this is my limited understanding. I haven't been following your discussion and I don't know how it affects the MWI.
you have to attach an a priori different Hilbert space of states to each space-like slice of spacetime
That is a valid formalism but then all the Hilbert spaces are copies of the same Hilbert space, and in the configuration basis, the state vectors are still wavefunctionals over an identical configuration space. The only difference is that the configurations are defined on a different hypersurface; but the field configurations are otherwise the same.
ETA: This comment currently has one downvote and no follow-up, which doesn't tell me what I got "wro...
These are extracts from some Facebook comments I made recently. I don't think they're actually understandable as is—they're definitely not formal and there isn't an actual underlying formalism I'm referring to, just commonly held intuitions. Or at least intuitions commonly held by me. Ahem. But anyway I figure it's worth a shot.
A proposal to
rationalizederive magick and miracles from updateless-like decision theoretic assumptions:(On Google+ I list my occupation as "Theoretical Thaumaturgist". ;P )