Just seen Keybase also exists, but the reference to .kbdx makes me think you mean KeePass?
If so I don't like the idea of publishing all my passwords to a public service like Nostr, even if encrypted. Seems like an unnecessary risk/honeypot scenario. There is the keyfile/password combo that adds another layer of encryption I guess.
I prefer security by obscurity, where a non-standard solution poses the biggest effort to attackers.