It seems that most of the ExB widgets cannot be configured to display data from added feature layers (fLs) by using their REST url or from feature layers generated from a query. An example is the table widget. The web AppBuilder's attribute table was able to create a tab for every fL that was on the map. Another example is the Query widget. The emphasis in ExB is using layers that are on the webmap.
Other that developing custom widgets, I don't see these WAB types of widgets to be introduced on ExB.
@RobertScheitlin__GISP any comment?
