I thought that it would be better if we can change the size of desktop icons one-by-one. I mean if you think that "Musics" folder is more important for you than "Documents", and you want to enlarge Musics, but not Documents. Can we add a new registry file to manipulate icons' size particularly? Is that possible to handle each icon individually?
You can't do that with default desktop, but some desktop overlays support mixed-size icons. For example if you don't need support for multiple screens, you can try BumpTop.