I am using and distribute the Daylight widget on the webscene around the office, every time there is a need for this type on analysis. It is possible to find similar tool in several softwares, but AGOL makes it simple.
I realized that the widget needs adjustments. The results instead of being great, are poor, because the widget is not taking in account the terrain and the high of the sun on summer and winter. That took me years to find out.
Make a teste on a deep valley and on the top of the surrounding mountains. The result is the same. Teste is again in ArcGIS Pro and the result is different.
Hope this is the correct forum.