I am also considering to use IPfire to block WU. but I can’t figure out how
Unfortunately All my links are being flagged as Ads- what irony,
I was hopeful I can use this Add-on by @timf that I can’t find any way to install it/
Here are some recommended domains to block, let me know how you got it to work 
Here is a WU list from November 2020
www.optik-bernd.de/WinUpdate.txt)
Here is w10 telemetry list: (could be out of date)
https://raw.githubusercontent.com/wlqY8gkVb9w1Ck5MVD4lBre9nWJez8/W10TelemetryBlocklist/master/W10TelemetryBlocklist
And here is a list of servers used by Spy Blocker: (Dec 2020)
You can add _v6 to the file name for a list containing IP6