Thanks Robert,
I would welcome any techniques that you have used to calculate fields from joined tables. The ability to join a table or feature class to any layer and populate a field based off contents from the joined data is a core fundamental GIS task that I have performed for much of my career.
For example, we used to populate an Elevation field in our old LGM geometric network sde layers using the "Add Surface Information" tool in the 3D analyst extension. Because the tool modifies the schema by adding a "Z" field, we would export the point features that we want to assign an elevation to and run the tool on the exported points. Then we would join them back to sde using the AssetID field and populate the existing Elevation field in sde. Is there a tool out there that will populate an existing Elevation field in a Utility Network feature service from a surface? Obviously because joins are not possible anymore, we need to find a new workaround.