these are interesting points. most reward point systems are just issued without any cost. zaps have a real cost (even if small). any “welcome zaps” would have to be given by someone. onboarding client or other users? the more automated the more game-able/drainable.
maybe a welcome channel/relay that shows new accounts who haven’t yet received a zap? and if/when it clicks for people who receive zaps ask them to pay-it-forward to send what they received