Since C4 is an unfamiliar development process for many, extra care needs to be paid to education about the process and one effective way to educate is gamification, however we don't have anything like that.
Proposed solution:
A game or interactive web app that illustrates in a fun way how smoothly a project can run under C4 versus other FOSS development processes. Could be something like those cooking games where orders come in and have to be handled by a chef.