Not really verifuable unless it's a burn (could be one entity sending onchain payments to itself).
Discussion
silent payments to generate address, then a private onchain zap could record and notify the receiver that bitcoin was sent to this address. I don’t think it would be difficult to verify in this context.
You're quite right, of course.
What I was pointing out was that it would be trivial to fake by simply zapping yourself. So, the transaction can indeee be verified but it would be impossible to know if it represented a genuine zap (rather than a self zap).
SPs on Nostr would be amazing. The pace of innovation here is crazy.