it wasn't clear from the demo, so it assumes that the people sending the ecash "zaps" are using the same set of mints? I'm not familiar enough with how cashu mints work for how this would work.

i think it would be fine in that case. as long as the client isn't accepting random ecash from random mints I can see this being useful.

having ecash stored in nostr is a bit sketch considering how people treat their nsec security, but its definitely cypherpunk af to have cash data that you can send around that lives in nostr itself.