How do you stop that discover updating nuisance
You just update. Only time it needs a restart is when certain system files or the kernel get updated and even then, it’s a pretty quick restart, unlike the 15-20 minutes Windoze takes. Most of the time you just update it and keep on keeping on with whatever you’re doing.
I see my update icon is red(Kubuntu w/Plasma desktop) so that means security updates. Done in less than two minutes and no restart. Gotta love it.
One bad thing Ubuntu or maybe the upstream Debian started recently is unattended upgrades. I think it’s for when a bug gets found that makes the OS vulnerable to hacking via internet. They usually require a restart and that’s the only way I know they happened. Suddenly get a popup out of the blue to restart.