In Map Viewer Classic the viewable fields in the pop up are the ONLY viewable fields when users edit the data. In Map Viewer the user gets ALL the fields when they edit the data - this is unnecessary and cumbersome for the user.
In appears that in in classic the viewable fields in an edit session are based on the pop-up, this does not appear to be the case in Map Viewer so we need another way to limit the fields available to the users while they are editing.