accounts-base and accounts-ui are awesome packages that happen to make a heap of assumptions about how you're going to reason about your user's authentication and session management using a system called Accounts. That's alright though, because accounts-ui isn't necessarily intended to be the de facto way to provide access to the API of Accounts. It's there to get newcomers started, to help more experienced developers quickly prototype their ideas, and probably only occasionally remain a permanent fixture of the UI.
Here's a look at how we can replace the functionality of accounts-ui with custom behaviours and appearances.
Via Jan Hesse