Desirable, but technically difficult, given gender-based titles:
Example: What do you call a male priestess? You call him a priest, which, barring a broad-sweeping errata, means that the "priest" can't use "priestess-only" spells.
Example: What do you call a female warlock? You call her a witch, which, barring a broad-sweeping errata, means that the "witch" can't use "warlock-only" spells.
Insurmountable? No...
Problematic? Yes...
-nihil