Basically I just bought a 4k monitor while also planning to use the old 1080p one. As it turns out the default size setting makes the fonts on the big screen too small, or the small screen too big. In Windows this wouldn't be an issue since I can just use multi scale. Ubuntu has that too, but it weirdly implemented and causes the smaller screens to be kinda blurly. The accepted solution is to use Wayland but it causes everything to be unbearably slow to me so that's out. Not expecting such an odd use-case to have an implemented solution but I'm eager to be surprised.