My largely baseless suspicion is that some of Solution Nine isn't actually 'real'. The space we walk is, but I feel fairly certain that at some distance out it's just a holographic image to suggest a larger city. I don't think you could fit one of those skyscrapers into the Everkeep itself.

I would point out that basically every city we go to is abstracted to some degree, though, usually by shrinking the 'expected' space, but a few do take the angle of 'you only get to be in part of this city'. I wouldn't be too surprised if the physical footprint of Solution Nine is comparable to all of Kugane.