RequireUsername in UserOptions of SphinxConfig

What is it supposed to do and how is it supposed to be used? - checking it concurrently with RequireEmail, for instance, effectively disables sign-on: after prompting for the name (email) and password, it stops with an error saying that the name is required. And no way to supply it.

In fact, there's no way to supply name or phone in the user registration process at all. - these are all standard properties of the User class, no extensions. And so the DB fields for these values are always NULL.

This is something we indeed need to polish. It will be implemented.

Is any development for Sphinx scheduled for this year?

Yes, we intend to have an update soon.