If { CSFS(nostr key, event ID) } else { CLTV 5 years in future } <normal spending conditions> They either put true and have to provide a valid sig for the event or put false and it'll verify the tx's lock time that it is at the expected date

Would have to hand craft the nostr note to make sure an exact time was included. 🤔

Also. The event id is not the signature. Its a hash

This seems scary for some reason, as it relies on serialization of data outside bitcoin. Would really need to be sure nostr serialization wasn't going to change within that time frame.