am just surprised that no one seems to have done it
Done what? If you mean eliminate quite a lot of the bar and brake lever structure in exchange for limiting riding position to in the drops, what you end up with is a lo pro. If you keep the whole of the bar but just fit vestigial brake levers in a place where they are out of the wind, see A. R. Engers
Smart enough to get the Regs changed to ban it. Obree is smarter, he had two ideas good enough to get specifically banned. Sakharov, of course, was even smarter had because he had a third idea, but his are not banned because nobody has tried to win a TT using thermonuclear explosives yet.
Done what? If you mean eliminate quite a lot of the bar and brake lever structure in exchange for limiting riding position to in the drops, what you end up with is a lo pro. If you keep the whole of the bar but just fit vestigial brake levers in a place where they are out of the wind, see A. R. Engers