So there’s the one set of couchdb login details, but that’s not used for encryption. There’s a separate encryption passphrase per vault, so you can store as many vaults as you like without worrying about other people using the database reading your files. My partner and I have a vault that we share (with shared passphrase), as well as each having our own vaults. This works best for us, but there’s also another tool by the creator to sync folders between vaults: https://github.com/vrtmrz/livesync-classroom