Just do a search for "arcane university" on TESNexus. I turned up 17, about half of which are actual cosmetic mods (the rest are minor tweaks or such).
Yes, you're right, of course. I should have been more precise: I was thinking more about mods like magic overhauls etc. that are also modifying the AU (but don't have it in their mod name).
I also forgot to mention that I am already aware of Midas Magic as well (which adds Midas' store to the outer courtyard).
[EDIT]In addition, I think I'll dare to focus only on mods that are compatible with the most famous overhauls (like BC, OOO UL etc.). Anything else should probably be neglected unless I want to run into an amount of work.
So just to avoid being bashed for not having searched myself
- These appeared to me to be somewhat relevant, so I'll be able to check them myself (partially done already, maybe someone can add some more information):
- Better Cities (of course, most of all!)
- Midas Magic (only minor changes)
- Arcane University Revamped
Arcane University 300 --> incompatible with BC, OOO and The Orrery
- Arcane University Mages Retreat
- Arcane University Revamped
- Reapers_arcane_University V_4
impeREAL Unique Districts Arcane university --> I assume that this has long been integrated into BC, hasn't it?