I actually looked at the engineering documents -- they weren't that detailed. It's not exactly what I'd expect from a build-ready project. That said, I'm not a civil engineer.
I'll also note, if you understood what those folks are about, that many of these folks would be happy to make a home out there if someone would pay them a normal-ish salary to maintain such a datacenter. I suspect this could end up economically advantageous both for the seasteaders and whatever company wanted to establish the datacenter.
(As opposed to the 2 weeks on, 2 weeks off, hazard-pay situation people are in for offshore drilling operations.)