Hey @Telefragger,
The snooze & restart options don't work the way I'd like either under Settings --> Agents --> Software --> Patch --> Default Software Update Plugin Policy -->restart tab. The way it used to work for us was we'd direct users to shut down at the end of the workday and updates would install. If they chose to put machine to sleep and ignored our recommendation, they'd get a prompt in the morning with the option to defer up to 8 hours (to get through the workday) at which point the machine would force restart. We had the policy settings set up that when they powered on the machine it would give the prompt within 5 minutes of them powering up so they weren't so into their work day they would often restart right away and not defer (that's why our setting is "during window check every 5 minutes."
Every since 8.0 (maybe it was before that?), we're seeing similar results where it just prompts user every 5 minutes regardless of our settings for deferrals because of our check every setting. It's annoying but the end result is users are annoyed enough getting prompted every 5 minutes that they restart.
I assume you've tried to change the window check every time and/or change the max deferral time, etc? If you had longer check in time I think it might help but would still auto restart if user doesn't interact with the pop up.
Here's our settings now in case it is helpful for you