Interesting, that I was not aware of. I've never run into a scenario where I've had to add/edit while offline.
When using vaultwarden however, you can be offline as long as the client can still reach the server (ie they are within the same lan network or are the same machine). You'd still be fine to add/edit while your home wan is out for example, just not on the go.
Plus there's the no-internet package mentioned in that link, but it's limited to the desktop application.