When tipping people that are not ready to be tipped by bitcoin I usually shared private keys with them, together with a disclaimer that these funds may get taken by me if they don't use them within 3 months. I printed that on paper wallets and so far I did not take any back but I fancy to believe I keep the backup somewhere in case I need to. I've seen waitresses throw away extra tips in Bitcoin right in front of me and I know that less than 5% did redeem the coins a year after I left them as tips, so by keeping a backup I can mathematically be 20 times more generous with my tips if I collect the lost coins later.

The same will apply to nostr users. They might not be that unlikely to "get" Bitcoin but I'm sure half of them will lose their nsec or not care about bitcoin ever.