> Is there a way (besides out of band software management) to make it auto install?
No, there isn’t. By design updates can be downloaded in background (it’s option “Download updates in background” in Updates panel in the UI) but they will be not installed automatically. User will have to start manually the update process.
To avoid pop-up messages you could disable ‘Automatically check for updates ‘ in the Updates panel and run ‘Check now’ at your own convenience.