Porting modern versions of QT to Windows XP

[K4sum1]

Somewhat recently, I've made a version of QT 5.16.15 compatible with Windows XP. It works for the most part, however there are some slight issues that I don't know how to fix yet.
https://github.com/K4sum1/qt5-xp

It appears to work pretty well in the limited testing I've been able to do with it. The issues aren't that major, maybe outside of this below. (please help fix)
https://github.com/K4sum1/qt5-xp/issues/7

The reason this is here under Research Network is because the issues, and maybe the possibility of a QT6 for XP. I haven't looked into QT6, but I believe if I were to try, I'd likely be able to do it. However the current issues, I'm not sure how to fix, and that's more what I want the community to help with. Although having a community QT6 for XP would also be nice, as I'm not sure if I'd ever get around to making it if I can just backport to QT5.
https://github.com/K4sum1/qt5-xp/issues