the instructions here discuss using the Meta Box Builder to drag and drop registration forms. However, since the implementation of AIO - there is no longer a 'Meta Box' section in the Settings page within the website.
How/where do I go to create a custom Registration Form for the Front End?
I figured it out. In case anyone else wants to know, to create custom user profile / registration fields, all you need to do is go to Metabox > Custom Fields. Click the Settings tab and assign the field group to Users and that's it!