Even that sounds potentially dangerous to me now, since it effectively means that some extra-long "correct horse battery stapler"-style passwords could be left

Even that sounds potentially dangerous to me now, since it effectively means that some extra-long "correct horse battery stapler"-style passwords could be left effectively unsalted. I mean yeah, 78 chars is an awfully long password but for some famous book or movie quotes maybe not outside the realm of possibility. Or if languages using double-byte characters effectively halve that cutoff then it really becomes an issue...