And make it possible to have password managers auto-type the username and password. Some sites don't focus the password field after the username field and so the "username -> tab -> password -> enter" auto-typing breaks.

In one especially bad case I encountered, the tab key after the username would focus on a "clear username" button which appears after entering the first character of the username. So the auto-typing of the password manager would enter the username, tab to the button, enter a password into the void and then click the username reset button, leaving the login form empty. Who needs a button to clear the username field in the first place? That's seems so useless to me.