[viraptor]

https://www.macrumors.com/2020/05/28/macos-ignore-software-u...

It's not quite forced, but you can't explicitly ignore. In practice I'm one accidental click away from an unwanted update now. (Each time need to remember to go one menu level deeper before updating)

[FullyFunctional]

I have this alias in my .bashrc and run it when I'm tired of seeing the red dot:

    nocatalina() {
      sudo softwareupdate --ignore "macOS Catalina"
      defaults write com.apple.systempreferences AttentionPrefBundleIDs 0
      killall Dock
    }

[viraptor]

The first command doesn't work anymore unfortunately. You'll still get it listed and it's a potential footgun.