I tried sending #[3] a PoW wall powered message allowing him to pull up to 10k sats of collateral attached to it using a LN wallet of his choice. I think he just gets too many messages on nostr or didn't feel like following the link to lnbits, fait enough.

Something like this can be used as a NIP in the future to combat the spam problem on social media using open protocols. The client would check whether the PoW sats are actually up for grabs and only present the message to you then. If it's spam you can claim the amount.