[LeonM]

I think it's explained quite well in the introduction text:

> M1 macs tend to have issues with custom resolutions. Notoriously they don't allow sub-4K resolution displays to have HiDPI ("Retina") resolutions even though (for example) a 24" QHD 1440p display would greatly benefit from having an 1920x1080 HiDPI "Retina" mode.

So, if you connect a non-4k display, the Mac will render in a way that won't look as sharp as the display could.

If you are in the marked for a new display, just but a 4K model (unless you have good reasons not to) and you won't need this hack.

[joosters]

So, if you connect a non-4k display, the Mac will render in a way that won't look as sharp as the display could.

That's not true. A display will happily utilise it's full hardware resolution. The problem, as I understand it, is you can't change the DPI of the monitor. You can configure a 2560x1440 display to use a lower resolution (e.g. 1920x1080 or 1600x900), but then the monitor itself will upscale this into a blurry full screen.

Tricking MacOS to change the DPI would let you configure the display to use all 2560x1440 pixels, but drawing everything bigger, at full resolution.

[LeonM]

You are correct, but I was trying to explain it a bit in layman's terms, since the OP did not appear to understand the intro text in the README.md.

[Grustaf]

But this is a fake display, it doesn't actually show anything. I think the explanation only makes sense for people that already know what the issue is.