Hi Aaron,
I can see that this is now implemented in ArcGIS Online and I can set up a refresh interval on the table itself too which is honored in the JSON.
My problem is that this doesn't seem to be reflected in Dashboard. My layers update every 30 seconds and I can see it when the web map is open, but have no effect on the web dashboard at all. Only the map item added to my dashboard refreshes.I've tested it in Chrome, Edge and IE. What else do I need to update/set up for the charts/etc. to work based on the table from my web map?
Ignore the above. It seems that the table comes up twice in the dashboard item configuration window. Once under part of the 'Layers from XYZ map' (although with a slightly different name for some reason) and another time under 'Other layers' that caused my confusion. If I select the table under the 'Layers from XYZ map' the dashboard items refresh automatically. Apologies!
Zoltan