To enable Software Update-only mode without using Profile Manager.
To enable this setting for a specific user account, log in as the account and execute this Terminal command:
defaults write com.apple.appstore restrict-store-softwareupdate-only -bool yes
To enable this setting for all user accounts, log in as an admin account and execute this Terminal command:
sudo defaults write /Library/Preferences/com.apple.appstore restrict-store-softwareupdate-only -bool yes<code>
To revert this change for a user account, log in as the account and execute:
defaults write com.apple.appstore restrict-store-softwareupdate-only -bool no
To revert this change system-wide, log in as an admin and execute:
sudo defaults write /Library/Preferences/com.apple.appstore restrict-store-softwareupdate-only -bool no