Surely “science” as a method is indifferent to interpretations with no observable differences.
Your point seems to be that “science” as a social phenomenon resists new untestable interpretations. Scientists will wander all over the place in unmappable territory (despite your assertion that “science” rejects MWI, it doesn’t look like that to me).
If Bayesianism trumps science only in circumstances where there are no possible testable consequences, that’s a pretty weak reason to care, and a very long tortured argument to achieve so little.
Finally this sequence of posts is beginning to build to its hysterical climax. It might be difficult to convince us that doomsday probability calculations are more than swag-based-Bayesianism, but the effort will probably be entertaining. I know I love getting lost in trying to calculate “almost infinity” times “almost zero”.
As a substantive point from this sequence, at least now scientists know that they should choose reasonable theories to test in preference to ridiculous ones; I’m sure that will be a very helpful insight.