I'm running a 2E game right now where i'm using New York. With the need to try to get the entrenched Seers out of Manhattan, the Mysterium opened up a secret Athenea, and expanded it to include room for all 4 diamond orders, and the libertines to share knowledge. It has an entrance in all 5 boroughs that are able to be moved around. It was inspired by a combination of Hogwarts, and Breakbills. Although each order still hordes there rotes, etc, and doesn't share easily...they do share some. Each order has a wing in the facility.

I call it "The Belgrave Institute".

It's existence allows for collaboration with the Pentacle that isn't easily challenged by the Iron Pyramid. Each segment of it I've been carefully figuring how the existing magic can control/create aspects of it without fudging any rules. Also as they expand it I roll to see if paradox is generated, and come up with ways the Abyss can twist a section of it, and how the awakened deal with it. It's a rewarding and dangerous resource all at the same time.

I like your Option. I don't think i'll go with it for requisitions, but you can get 1 dot in status in any of the other orders regardless of which one you belong to. This allows for people outside the orders to get things like Techne, and Adamant Hand. I really like the Favour condition. That's awesome.