This is a sequel to Keeping up to date using Munki without bothering users, which discussed a few approaches to not bothering users with Managed Software Center updates.
I'd tried controlling it with rescheduling the launch daemon, which works well for desktops, which are plugged in and can be scheduled to be on at specific times—not so great for laptops which can be sleeping at random times during the day.
I'd also tried setting the DaysBetweenNotifications client preference (full list of preferences on the Munki wiki), but that was still giving mixed results.
Special thanks to Ben Goodstein (on the Mac Admins Slack), who gave the suggestion of using the SuppressUserNotification preference on some kind of a schedule.
So right now I'm trying out (and I believe it should work), having a Munki nopkg manage that setting based on the time of day, day of week, and date of month (basically if it's toward the end of the month and not during the school day, I actually don't want notifications suppressed; otherwise, I always want them suppressed).
Here's my nopkg for SuppressUserNotification—feel free to tweak to suit the needs of your organization or school. I may also revise it based on my testing with users.