I don't mind much if bundle the "Prof-Gnome" theme and use it by default or just document the way how themes can be installed and used on Windows.
Maybe it's a bit too mac-like for Windows, I don't know. It's probably best to use a theme that looks most native to the platform (while being usable though). I'm wondering how would e.g.
https://github.com/B00merang-Project/Windows-10
look like on Windows. Again, it seems to use svg resources so I think librsvg will be needed.