Hi @adminNWA ,
The fetch full installer command was introduced on macOS Catalina. So, if you were to run that command on macOS Mojave and older, you'd get an error. As of now, its only benefit is downloading Catalina on Macs that already have Catalina, but it will certainly be helpful in the future.
If you're looking for a method of deploying Catalina, HCS has a great workflow.
You can request legacy installers going back to 10.13/High Sierra. It's actually pretty handy.
--fetch-full-installer Install the latest macOS Installer --full-installer-version The version of macOS to install. Ex: --full-installer-version 10.15
Older installers should still be available in the MAS for you past that.
Anybody else getting
SUPreferenceManager: Failed to set object of class: __NSCFConstantString for key: LastRecommendedMajorOSBundleIdentifier with error: Error Domain=SUPreferenceManagerErrorDomain Code=1 "(null)" Install failed with error: Update not found
softwareupdate --fetch-full-installer with or without