I'm hoping someone can elucidate on the subject of Apple Software Update JSS.
I have a number of 10.13.2 Mac Mini's enabled with Content Caching. If I point my clients to Apple's Software Update Service via a JPS Computer Policy, will my Caching Servers mitigate the WAN consumption by properly caching all requested updates?
Mac Mini's 10.13.2, Content Caching Enabled
You should enable Software Update service on your Server.app and point all your clients to it instead of Apple's server via terminal command:
sudo defaults write /Library/Preferences/com.apple.SoftwareUpdate CatalogURL “http://your.server.com:8088/index.sucatalog”
Regarding caching, yes, just make sure your Server.app has the proper settings.