I use a 4k display and I like to have big icon sizes in Qt/KDE toolbars in my programs.
I tried shotcut briefly and it’s just unusable with it’s extremely tiny (on my screen) icons. Qt applications in general are fine because the icons scale either according to KDEs settings in KDE or qt5ct in other desktop environments. But that does not work in shotcut.
A brief look as to Why, what is Shotcut’s problem - it’s a Qt application after all, it should work, revealed that you’ve actually hard-coded tiny icon sizes into the xml files. Why would you do this? I have no idea. I encourage you to please stop.
To test how it’s fixed, I did a quick test of /usr/share/shotcut/qml/timeline/TimelineToolbar.qml and simply replaced “implicitWidth: 28” and “implicitHeight: 24” with nothing (removed all instances). This made Qt use appropriate icons-sizes.
You should probably remove all the tiny hard-coded icon sizes. I guess I could go through the program and fix it but I’ll just stick with kdenlive