You guys are way to safe to have any fun.
I agree, however, that manual brakes would be much more reliable (SAFE, OK?) than rigging up a power assist system. Probably just as much work, too. But don't stop thinkin' and tinkerin', Ben.
I thought I read somewhere that somebody drilled holes in the back of the booster to relieve it to atmospheric for easier pedal force. Was that the Mullet? Or did Darin do that in the Forkenswift?