Registration of "registered users" (easysocial + JFBConect)

I'm not really sure what you mean. Users can normally only have one account on your site.

Is what you're trying to do something you already something you have set up in Joomla! itself? Or is this something you're looking for help on setting up for the first time. If it's something that's just not working in JFBConnect but works with normal Joomla! or EasySocial accounts, we'll gladly help investigate however we can once we understand thongs further.

Thanks,
Alex

We have already set this up in Joomla (the first part where people can sign-in using JFBConnect)

Do you have both steps setup within Joomla already, outside of JFBConnect? I'm still not sure how you plan to do this or how JFBConnect would be a part. What you're looking for isn't something we do within JFBConnect. However, we can usually work with different extensions or configurations you have setup to let JFBConnect augment a flow or process you want to use.

From what I can tell above, you're looking to have JFBConnect have some sort of secondary upgrade process for already registered users and that's not something we do. We'd recommend looking into some other profile management extensions that may have what you're looking for. If you're already using one, please let us know more about how you're managing profiles.

Thanks,
Alex