For Installing ArcGIS Desktop Silently by script, I believe, if I have an on site portal and need to redirect all installs from ArcGIS online to said portals, that this should be a scriptable option. This is in the same way as pointing to the current license managers to consume a concurrent License. I should not have to go to each and every system and redirect the application manually or have my users add the Enterprise Portal for ArcGIS individually.