Correct me if I'm wrong, but once a project is greylisted, anyone with (presumably gradually decreasing) RAC on that project is SOL and loses any GRC they would have been making on it.

Assuming I'm not missing something here (a big assumption..), that sounds like a pretty good reason to be against it as implemented... Seems a bit unfair to retroactively decide to not pay a cruncher for crunching already performed.