I've been trying to figure out a similar system when I looked at potentially making some software source available. I wanted contributors to receive a portion of that months sales for the software, possibly including future ones as well. Some kind of development equity setup. It fell apart when you start trying to codify/cement how the equity is awarded, nothing is ever clear cut when considering level of effort/impact.

While this project tries to solve the money aspect (not sure benefit of it vs other sponsor distribution platforms...), it doesn't solve the biggest issue: how do you figure out who gets what. I can't imagine the kind of vitriol it would generate in the face of CoEs and modern meritocracy controversies for open source projects. Money corrupts everything.