what would be a good value for maxpixelzoom on modern monitors?
Pixels on modern monitors are usually smaller than the human eye can resolve, hence with a maxpixelzoom of 1 small details would be lost on such monitors.
My considerations so far: The limit at which the human eye perceives an edge as sharp is about 2 arcminutes. I assume this as the limit to perceive pixels. To perceive blur, at least two pixels would be needed.
A monitor is seldom viewed from nearer than its height, which is equivalent to a vFoV of 53°. Hence, a maximum of 1590 pixels (vertically) could be resolved and if you accept minimum blur only 795 pixels are needed. A 4k Monitor can have up to 2160 pixels vertically, so maxpixelzoom should be 1.36 for a display at the sharpness limit or 2.72 to show a tiny bit of blur at the nearest usual viewing distance. Further away, it would still look sharp.
Does that sound correct?