Allow adding other default profile fields to signup dialogue

I’ve been using this tip What are best practices for encouraging / enforcing profile pics? to remind new users to fill in the “Location” field in their user profile. While I do appreciate the ability to customize the welcome message, it’s not working very well. Almost none of the new users that have signed up in Discourse have filled out their Location, whereas almost everyone that signed up at the forum that I migrated from had filled it in because it was shown as an optional field during the signup process. The forum has a large international userbase, and sometimes the answer to user questions depends on the location of the user that asked the question. Knowing the user’s location also helps other users to overlook some posts that could be taken as offensive, as the Location field helps to explain cultural differences. And I’ve even found it useful on many occasions when a suspected spammer makes a typical “Thanks great post!” first reply to get started, and they fill out their location as “New York” but with an IP address from Timbuktu.

I assumed from this post that the signup dialogue couldn’t easily be customized:

But then I discovered that other users are even having trouble with too many custom fields appearing during signup:

So it seems kind of strange that custom fields can be displayed and made optional or required during signup, but default fields such as Location and Website apparently can’t. Am I misunderstanding something? Or if not could this feature be added? Thanks!