I did something like this at my last house but somewhat more covertly, with monitors going into storage but having VESA quick mounts hidden near the Ethernet hubs, a few on articulating arms that could pop out near couches etc.

My setup only supported 12, but was designed in a way where you could have 3 teams of 4 or 4 teams of 3 that got their own private area so they could more easily conspire against their opponents.

I think my most interesting design choice was that I had half the machines routed from the attic and half routed from the basement. Part of this had to do with retrofitting my setup into a house over 100 years old, but I thought it also worked very well. If I were to do it again, I'd probably mount all of the computers in the basement, since it would provide extra heat (for the house) in the winter and stay cooler (for the computers) in the summer when under load.

I have since moved, but haven't bothered to make it happen again. Life with kids is too busy, and I've largely abandoned the hobby because I believe it would not be a positive influence given the particular quirks of my children's personalities. Slowly easing back into the waters with board games, though.

This sounds interesting! Do you have any photos?

From the description this sounds like the most elaborate setup I've heard of aside from my own.