Did 0.20mm horizontal dot pitch CRT monitors even exist?
I've forced the OS to send resolutions that high to smaller CRTs before but that doesn't mean it's properly displaying all 2048x1536 pixels. The monitor only has so many phosphor dots, beyond that limit it's just aliasing.
I also found with CRTs that you could choose any two of the following when selecting a display mode:
1) High resolution
2) High refresh rate
3) High detail (i.e. low blur)