When it says user, it is probably not referring to you but the process.
I just updated two systems today. My second system was finally seen and the upgrade installed normally. The other, unqualified system, I upgraded with the Install Media and it went all the way to .521 without my having to install another update. I had done the Registry change as Microsoft indicates.
If you want to supply the setupact.log, I can look at it. The fact the upgrade attempt only seems to have lasted 4 minutes could mean there isn't much in it, but you never know.
I already went through the upgrade of four other machines, without any problem, either with W.U. directly or with the MS ISO file, and they all went up directly to 22621.521.
This box also upgraded fine on Sept 21, then it started spitting up the messages when I tried again 2 days later when I was trying to see if MS fixed the bugs that had been reported.
I already attached the setupact.log to the FBH report, I don't use OneDrive so I don't have a way to upload the file for you unless you give me a place where I can upload it.
Now MS is just popping up this useless message from W.U. without any explanation of why they are putting a Safeguard Hold.
I already worked around this stupid hold and upgraded the box again and it does work fine without any problem.
I just want to keep this specific system as is to see when MS will finally solve the issue or notify what is causing the Safeguard Hold.
I don't have any of the issues they list in the known problem list. And the details for my Safeguard Hold are not available yet. 🤣
I'm just curious to see how long MS will take to get a solution for whatever they think are detecting. 🤣🤣

Which registry change are you referring to? I did not need any registry change to do the upgrades on any machine. 🤷♂️
I'm testing this R.P. build on the same box.
Edition Windows 11 Pro
Version 22H2
Installed on 9/27/2022
OS build 22621.607
Experience Windows Feature Experience Pack 1000.22634.1000.0
I will restore 21H2 to check the MS W.U. Safeguard hold again tomorrow. 😂😂😂