In ArcGIS Online, labels are based off of centerpoints of polygons for sure. However an offset would be nice if it exists. I know this has come up several times and am curious if there is a way to do this. Arcade maybe?
Lines and points I am not sure about, but the polygons are definitely centerpoints for labelling.
Hope this helps a little, I'm interested to find an answer so I can put it to use. Thanks!
Jansen Lyons - Records and GIS Section - Public Works - City of Rio Rancho, NM