Cool proposition but because of your onerous terms you are self selecting for bottom barrel. In startups (where there is a power law distribution of outcomes) it would be much preferable to offer more generous terms and simply be more picky selecting for founder competence. Also- need to figure out statute of limitations: who decides when one MVP stops and another begins? What if a freelancer takes your money hacks up a bunch of MVPs and learns enough to do the full swing by themselves?