I don't think this was intentional. If it were intentional, they would have done the same thing for Vista and 7. Plus, I saw that the System32 directory was bigger after installing the SMQR (saw this in the recovery environment), that is proof it ACTUALLY installs something, so I guess there are just some files that don't work on client. I have 5.39GBs (5.27 on disk) of System32 directory on the June update, and 5.85GBs (5.69 on disk) in the unbootable state after applying the whole rollup.
The .NET update also still has client packages in the manifest. The pkgProperties in the MSU root still mentions Windows 8.1 Client and Windows 8.1 Embedded.
I wonder what happens with the Desktop Experience server role, that is essentially a Client-like OS. Thanks for the tip, I'll leave a link to it here: https://forums.mydigitallife.net/threads/dism-new-windows-utility.59389/ I do believe it may dump the updated components into the WinSxS cache, resulting in the size increase. I'll fuss with it a bit more, and edit this post if I find anything relevant. I'll take inspiration from here: Thereby getting the virtual machine fully updated with 2025.06 status, before any further tests. I am also testing with the option: Code: Bcdedit.exe -set NoIntegrityChecks Yes to see if it has any impact. My two cents. Thank you. P.S.: Continued at https://forums.mydigitallife.net/posts/1884097
Some of these things were part of my course of action. I was using my June 2025 2012 R2 ISO right now to test everything. It just installed. Time to test! I already did the DISM++ thing on my actual Win8.1 laptop, resulting in nearly no changed files, and build remained at 9600.22620 (June build). It is currently searching for updates (ESU works OOB on this ISO). I'm also going to disable integrity checks.
If nothing works, I'll just wait until the August update and if that doesn't work either I'll just install Server 2012 R2 and use it like if it were 8.1.