Has anyone ever had luck stopping automatic updates (not just pausing/delaying them?) with Windows 10?
Yes, mainly via the methods described in that thread - disabling automatic updates via Group Policy, disabling the Windows Update service in the Services control panel, deleting the built in Scheduled Tasks that re-enable all this stuff, disabling automatic device driver updates, and (if you really want to nuke the whole auto updates feature in Windows, not just disable it administratively), you can even delete the automatic update service using the command
sc delete wuauserv from an administrative command prompt.
I also use a Scheduled Task to automatically reapply these steps on every re-boot just in case any *other* software updater decides to tamper with this policy. That and another scheduled task to reapply all my anti-spyware registry settings. I blackhole Windows Updates servers at my router as well and disable peer-to-peer updates on my network. When I want a specific update, I download it and apply it manually. After taking a good full system backup, of course.