I use grlevelx. When I upgraded from v2.21 to V2.7 the metar and cwop icons became too large.
I tried to get support with this last year but never had an answer. I went back to V 2.21. More info follows...
Last year Rick Hickman worked on a problem with the LARGE metar and cwops icons on 4K monitors using the latest versions of grlevel3 software.
He replied in the grlevelx forum that
"Yes, however all I learned is that all of the icons will have to be remade from scratch due to this DPI update. Since we don't have the original "master" files, this will take some time.
I never heard back about this problem which still exists.
See samples below of before and after version 2.21.