Telemetry isn't even the nasty one. Look for "activity" in your DNS logs. Just try to block that... All the Windows 10 machines (home and pro) on your network will freeze up and hang for extended periods of time. Microsoft wants to know every time you spawn an application, what it was, who launched it. It doesn't matter how you block it, NXDOMAIN, REFUSE, fake IP, null route, all of those will cause machines to hang. A tcp-reset will reduce the impact a little.
[Edit] MS may have wised up and consolidated the activity endpoints / vips into another endpoint. You may have to clear cache on the PC and your router, reboot and watch DNS requests as you launch applications to see where they moved.
To stop this behavior requires registry changes unless you are on Enterprise or LTSC in which case you can use GPO. There are some free programs that will do the registry tweaks for you.
Here is a video talking about manually changing some things [1] and they link to free tools that can do the changes as well [2].
[1] - https://www.youtube.com/watch?v=tgW7iXejfqQ
[2] - https://www.oo-software.com/en/shutup10
[Edit] MS may have wised up and consolidated the activity endpoints / vips into another endpoint. You may have to clear cache on the PC and your router, reboot and watch DNS requests as you launch applications to see where they moved.
To stop this behavior requires registry changes unless you are on Enterprise or LTSC in which case you can use GPO. There are some free programs that will do the registry tweaks for you.
Here is a video talking about manually changing some things [1] and they link to free tools that can do the changes as well [2].
[1] - https://www.youtube.com/watch?v=tgW7iXejfqQ
[2] - https://www.oo-software.com/en/shutup10