Re: MPLAB X with 4K Displays
I have run MPLAB X on 4K screens for over four years now.
The first 4k monitor I used was 28". I found the fonts for many applications to be too small, and what made it worse was in a multi-monitor setup. At one point I ran three 28" 4k monitors. Windows scaling just makes things worse, as it doesn't work properly with all applications, as many have since found.
The only way I made a 28" work well was to use 100% scaling and force to a lower resolution, in my case 3200 x 1800. This non-native resolution has the side effect of being slightly blurry, but I found that it was by far the best compromise.
About 2.5 years ago, I switched to a single 32" 4k monitor, which I use in its native 3840x2160 resolution and 100% scaling at 60fps. This is without doubt the best solution I've experienced, and I've used it ever since.
One further compromise back in the early days was that I could only run the screens at 4k30fps with the adapter hardware I had. Although 30fps is usable for coding, the mouse cursor has noticeable jerkiness and slight latency as a result. You get used to it reasonably quickly, but it's sub-optimal.
More recently, in the past couple of years graphics cards and integrated graphics have caught up to support 4k60p through HDMI 2.0 as well as Displayport 1.2. The more common HDMI 1.4 will only support 4k30p. To support 4k60p with integrated graphics, you need both a processor [Skylake or later] and a motherboard that supports it.
Note that I am of a vintage where I do wear glasses!