It’s the default under both Windows 10 and Gnome 3 for hi-dpi displays. In fact, it’s near impossible to get fractional dpi working across the board on Gnome 3.
I'm not sure how, but GTK3 applications violate the layers and are not affected by the nVidia setting. I think it's because nVidia sets a fake Xorg resolution (e.g. twice your actual) but GTK3 sees through that and uses its own internal dpi setting. I also presume this would be the case regardless of whether Gnome 3 is your DE/WM or not.
Is this hard to do? Caveats?