Yeah, you can import keepass files, and this is how I keep things synced personally. I haven't worked on exporting to Keepass format, so I only mske changes in Keepass and then periodically re-import.

I see a KeePass mirror on your gitlab. Does it already synchronize the passwords stored in the hardware with KeePass? https://gitlab.hax0rbana.org/signet

Yup, exactly.

A yubikey can only store one password, so you can't use it to log into accounts that take passwords, enter passwords to decrypt files and so forth. It does second factor auth, FIDO2 auth and things of that nature. #Signet does store passwords (and other secrets like seed phrases, answers to securit...