In my experience HiDPI is pretty well supported in Linux these days but mixed DPI over multiple monitors is still somewhat hit-and-miss. I've resorted to runnin

In my experience HiDPI is pretty well supported in Linux these days but mixed DPI over multiple monitors is still somewhat hit-and-miss. I've resorted to running my XPS 15's built-in screen at 1080P when I have my 1080P external monitors connected. Shame as I did pay extra for the 4K option! Independent scaling per monitor is supposedly supported in Wayland and just around the corner in KDE so I live in hope. I hear it's mostly working in the very latest versions of Gnome now at least, although I couldn't get it to work. (I appreciate that this is a thread about BSD - I'm just pointing out that the situation in Linux isn't much better)