banger I dabbled with Win 11 under a VM but it wouldn't install under boxes
Windows 11 checks for several entries in its registry that must exist, or must be set to "1" in order for it to run. When that version was new, I found documentation that explained what those entries are, and which allowed me to install and run a Windows 11 VM using VirtualBox. I'm sure the same advice would apply to GNOME-boxes, so it's worth a quick search in the forum, or online.
The alternative I prefer is to simply use Windows 10 while it's still available. It allows me to use an offline account instead of being tied to the Windows 11 ecosystem, which is important to me. When it's no longer supported, I'll need to decide what to do next. Although I was a Windows enterprise software developer for decades before I retired, I now have little need for that operating system, so I've only used the VM to run the odd program that doesn't have a Linux version. And I haven't really needed it for a very long time.
So, if you really want a VM that runs Windows 11, it is (or at least it was) possible to do that. Just see if you can find the documentation you need, and make a few quick registry changes using regedit. Unless Microsoft has gotten even nastier since Windows 11 was new, it should still be easy to create such a VM using a Windows 11 .ISO file. Good luck with your quest.