At the end of the day, my nostrPubkey on my lnurl endpoint says to only trust zaps from my lightning node. I can use this to trust that the zaps I receive are legit. Zaps are tied to sender pubkeys. If i see a zap from someone, then I know that person initiated the zap and most likely paid the zap. I can use this to improve that pubkeys spam score. If they are a spammer and send me 10000 sats to pass my filter and start spamming me, then I can just mute that key and they have to send me another 10000 sats to try again.