I thought I'd spend a few lines in irb and implement two.io for you right here in a comment ;-) Here are the available two letter io names from /usr/share/dict/words, /usr/bin commands, and bash builtins: ah.io, ay.io, di.io, ea.io, ey.io, fa.io, fc.io, fe.io, fg.io, ha.io, he.io, ju.io, ka.io, oe.io, or.io, ow.io, pu.io, ra.io, te.io, ti.io, tu.io, ut.io, wa.io, wi.io, wu.io, wy.io, ya.io, ym.io, yn.io, yr.io, du.io…
It's pretty rare a NIC allows two letter domains so it might be a general limitation, but they are possible. Either that, or our domain (ep) is just a very persistent hallucination.
I'm tempted but I already own "no.gd" (a rather undiscovered TLD if there were one - and they allow 2 letter domains!) and have little enough use for it already..