there is a very complicated equation to solve as far as making there enough incentive for whales to keep the SP above 250 MV powered up
I went through the math on this... i think on the can opener post.
if you found a way to exclude the steemit account (which, i don't take it as a given that you could. Or that TPTB would be cool with it even if it were possible), and you limited it to just 1GV and above whales, you would be able to offer about 50K sp a week divided up among about 150 G vests, which amounts to around 260 SP a week per Gvest if divided porportionally. This amounts to around 2.6% per year non compounding.
That gets cut in half to 1.3% APR if you include the steemit account. I didnt go through and do an exact count, but my spitball guess based on some quick tallying on steemdb is that if you added in all the accounts between 250MV and 1GV as well, you would end up with something like 1.7% apr not including the steemit account and just under 1% including the steemit account.