Besides the challenge, what would be the advantage to having a PW manager or 2FA manager on Nostr? It seems like those would be better to be non-networked? 

I guess you could use vaultwarden and publish the database file via a relay to sync between devices? 

 You would make your own app that is nostr native and it would connect to your private relay instead of private vault warden 

 Interesting idea
Things are moving so fast I can barely keep up 😅