[thanatos519]

> With X, all monitors must share the same pix density

`xrandr` allows different per-output scaling.

For example if you have a 4k laptop and and 4k monitor that is 50% bigger than the laptop display, X will pretend that the monitor is 5760x3240 and scale down to the actual pixels.

Having said all that, I dislike scaled anything, so I choose a pixel density between the highest and lowest densities of my physical devices, and manually pick the font size of my terminals.