I think it stops being science at that point though. For example, if someone made a quantum computer powerful enough to factorise large numbers then that would appear to disprove superdeterminism. However, proponents could always argue that the computer only works because the universe conspires to make the human entering in the numbers to be factorized enter specific values which the computer will then know the factors of.

I'm not a physicist though, so I might have something wrong here.