@bear_necessities What's nailed down (but not in any practical way) is that the geographical setting is NYC, with grid representing bits of Brooklyn with its hedge safe house, and bits of Manhattan with another one, with oscillating rival/ally relationships between the two. And Brakebills. While hedges couldn't go to Brakebills easily, students and faculty and alumni can all use both city and school.
You are right about the wide spread, but I want that. And about the cliquiness risk, which is pretty big for any MU and made worse when you set stuff that encourages and enables characters avoiding one another.
BUT I set a lot of store on letting people play what they want if it doesn't roger the game-world. So it goes like, "Hmm, you might have a hard time finding meaningful RP as a talking, teleporting, cigarette-loving bunny, but hey, roll with it so long as you don't come bitching at people if it doesn't work out," and I'll credit the player with either wanting to give finding meaningful RP as a bunny a try regardless of the challenges, or with getting a giggle out of just repeatedly posing plopping into the room with their wiggly nose and saying "Eat my ass," and either enjoying it or finding something else to do.
The hedges and the after-Brakebills stuff is more interesting in the show and books, but I get the impression more people want to play Brakebills than don't. Also, it has a massive advantage in that student characters can be drop-in builds. You've already pretty much got 'late teen to mid-twenties, was a 'gifted' child, probably has a trauma, magic.' It's quick to get from there to playable, especially if it's my game because I'll let you rework your sheet during your first couple of weeks, and let you have many alts if you want, and do not give one fuck if you abandon the character, and prioritize approval speed.