It's not something I'd use too much, but it does make sense. You'd need a tab for saved configurations (perhaps just use the "Favourites" tab), a "save setup" button on the hanger menu and a save file requester to name the file.
Me410 ground attack
Me410 anti-bomber
Mosquito JABO
Mosquito interceptor
Etc.
Yes, this is a convenience, not a must-have, but software (and AH) is a game of steady, incremental improvement. Otherwise we'd still be saying "Wouldn't it be cool to have multi-player air combat simulator?"