Comment # 3 on bug 1089886 from Stefan Hundhammer

I don't think we are doing anything special with font sizes in the YaST control
center. 

I am pretty sure this affects all pure Qt applications (KDE applications
probably have a lot more magic what font sizes to use).

There used to be a program "qtconfig" to configure the fonts used by Qt
applications, but starting with Qt 5, this no longer exists; Qt 5 and later
rely on getting font settings from the desktop, however well that works. You
might just have discovered a case where it doesn't work so well. I am just not
sure what we can do about it from the YaST side; very likely this will have to
be addressed on the Qt level or maybe (less likely) from the desktop side.