Do you have in mind a mechanism to flag dishonest / scammers / bad actors? NIP-56 reports or NIP-32 labels would be a possible place to start.
I suppose it would be simple enough to calculate the number of successfully completed projects score, something similar to what eBay does, but do a GrapeRank-weighted sum rather than a simple sum to screen out fake projects.
This reminds me that I’ve been wanting to export WoT scores using nostr:npub1gcxzte5zlkncx26j68ez60fzkvtkm9e0vrwdcvsjakxf9mu9qewqlfnj5z ‘s NIP which you could use to import GrapeRank scores for the above calculation.