We publish server-based web layers with data from data sources registered with our federated servers (ArcGIS Enterprise 10.6.1, soon to be 10.7.1), using the data option “Reference registered data”.
In this scenario, the feature layer property “Export data” is not supported according to your matrix (and my testing), see attached image.
It would be very helpful if our users could export data, for instance shapefiles, from these web layers.