The grid isn't a multiple of 200x50. I've said that I don't know how many times. It's 200x45 for the rooms plus 22 for the ducts. I've not changed that since I reworked the thing. And besides Nuke, your stuff is already made to fit, if you will look at what I've posted.
As for the ducting-every-other-floor requests, I just have to respond with "why". That would serve only to make the entire thing even less stanndard. Again, it's not like I'm denying space; 2-story rooms have more to work with now than they did before.