Well, since these projects are inherently broken as they are, perhaps if they made them less game-breaking in themselves, an option for a repeat at some point would be viable. I'm not sure how this exactly would work, but given how real life has had "world games" (Olympics) every 4th year and "world's fair" (world exhibition) I don't know how often, but at least repeatedly, it might not be a bad thing if these events happened repeatedly once voted through, but with less extreme (or shorter duration) benefits for the winner each time.