I installed opensuse Leap 42.3 on dell xps 13.3 inch QHD+ (3200 x 1800) and I have the big problem with resolution it means the letter and icons on my laptop desktop were way too small.
I've temporarily solved this problem by changing the scale to 2 (in Display Settings) and changing the DPI value to 192 (in font settings).
But still, some other applications require manual changing in font size etc.

But now I have a issue when I am trying to connect second monitor with the second monitor - 1920x1080 - (dual monitor settings), now the resolution on second monitor is realy bad, but now on the second monitor the icons and letter a too big (completely unuseful) ;(.
Maybe somebody knows how to change the scale or DPI for the second monitor?

My laptop monitor is 3200x1800 (but I change the scale to 2) and my second monitor is 1920x1080.