All the monitors I've tried will scale vertically and cannot reduce size. There will always be some moiré at high res. Best way is either all white or all black background. On the other hand I think it's for the best since old CRT monitors were 4:3 ratio and newer non wide LCD are 5:4, which means the pixel will be square. You can confirm this in the pic I took, the icons and text are well proportioned.
1040STfm (Spanish), SM125 monitor, Megafile 30, 520STe (4MB), 520STfm (XtraRAM 1MB), Mega STe (4MB, 120MB HDD), Mega ST4, TT030 (4MB+64MB, 1.2GB HDD)