I actually had exactly this idea with my YC knock-off, HMC INQ.

The first cohort (5 cos in 2017) I offered them to all pool some of their equity. But first I polled how much each would be willing to give. The results were 0%, 0%, 2%, 5%, and 20%.

So, I abandoned it. Ironically the one that offered 20% is doing the best so far.