I'm using the following registry settings on my PC, and never had Windows interrupt me for updates:
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU]
"NoAutoRebootWithLoggedOnUsers"=-
It seems to be working for me, but other people say its no longer effective: https://superuser.com/questions/1066441/is-noautorebootwithloggedonusers-still-supported-effective-on-windows-10