I have been using #WindowsServer Core as a development VM, because I need to test my program for Windows users. I know this isn't recommended, because Server Core doesn't have much of a GUI, and is missing a lot of GUI-related libraries, so some stuff doesn't work right, however, VSCode (and Visual Studio) work just fine, and I've been getting by with Powershell, 7zfm, Retrobar (substitute taskbar), and Floorp (Firefox mod). The GTK version of #VICEEmulator doesn't work, so I've been using the SDL2 one.
I think I like this in some ways more than using actual Windows. It's definitely lightweight. I wish that it had DirectX support so I could try running games with it