What ArcGIS Pro geodatabase mechanisms make an item unusable in ArcMap?
Anything else?
I’m aware that ArcMap support is ending. But ArcMap is still useful for troubleshooting purposes for select users.
I would add Utility Network, Updated Annotation (I think) to the list
Not sure this meets all the needs but a start...... https://enterprise.arcgis.com/en/server/latest/manage-data/windows/client-geodatabase-compatibility....