Accidentally opted to "Install Update Now", can't change option, so purposely blocking restart loop with app close dialog confirmation, but MacOS keeps trying to restart every ~30 mins

Somehow, an auto update from 11.2.1 --> 11.2.2 got through after explicitly blocking auto-updates via the Pref Pane (this alone is unacceptable, but not the concern here). Not wanting to play "Tag" with the notification, I tried to select the "Remind Me Tomorrow" option, but mis-clicked and selected "Install Now".

Nonconsensual auto-updates seem to be a persistent problem in MacOS, so fortunately, my iTerm2 has a confirmation dialog on close that times out the restart. However, all other apps (Chrome, SublimeText, Slack, etc) close, which is pretty annoying.

My confirmation dialog successfully prevented the restart, but the OS keeps trying to restart the close-everything-and-update loop every 30 minutes or so. I shouldn't have to choose between my work closing every half hour, or my computer being out of commission for an hour, but there is no option to cancel the update entirely.

Is there a manual workaround here?

EXAMPLES OF BAD ADVICE

• Restart computer
• Use the PRAM/NVRAM shortcut
• Boot into recovery and reinstall MacOS
• Uncheck the 'Automatically Keep My Mac Up to Date' option in the Pref Pane
• Uncheck anything in the "Advanced Options" modal of the Update Pref Pane
• Quit the app blocking the restart (yes, I have to include this...)

EXAMPLES OF GOOD ADVICE

• Anything I can do in the Terminal (e.g. modify a system-level cron job, remove a lockfile, change a plist value)
• A process I can force quit from Activity Monitor