Ah fuck.  It is a good point.  Typing the same password on a different kind of keyboard may actually give a different unicode representation.  I did know about this but it didn't come to mind.  This isn't even an scrypt specific problem, and it rarely presents, and people have probably learned not to use combining characters in their passwords.  But the edge case can be solved by normalizing to NFKC.

It would be a breaking change. 😆