Thanks for the info, will try this when I get around to it. But this sounds like scaling a low res image to fit the pixels instead of native HiDPI support, is that right? Then it will probably be blurry?
Edit: Maybe you meant using a native 2x scale paired with downscaling. Interesting, sounds promising.
I'm not denying it's a pain and Windows/MacOS are miles ahead, but this is how you can get by on Linux with X. I use it daily for work and media, on a variety of monitors.