what about all the historic events that deliberately avoid a formal checkin? e.g. protests & strikes? same deal with a p2p scavenger games, is it really visibly fair if there isn't a way for anyone to just permissionlessly purchase the things to hide? unfortunately poap design is top-down w/ strict networking.
the reason I reference the scavenger hunt is the idea that a contest for qr codes is lowkey a really sticky guerilla marketing campaign for URLs. and potentially an undiscovered form of sybil resistance.