Following up on this:

KeePassium is great and very fast. However, when you have a form to create a new account/password in an app or on a webpage it doesn't yet hook in like native Passwords app and let you store the new account or TOTP. It looks like this is being worked on.

Bitwarden did support this *in the browser* with their browser extension. But since KeePassium is doing the OS-level integration not the browser extension it seems there are additional challenges here. But the benefit it is that it will work everywhere a password field is detected

I can live with the manual account/password creation workflow for now