I have installed some KDE and GNOME applications on the same computer. I use the applications at the same time. I find, I often hit the wrong button when I see "OK" or "Cancel" or "Yes" or "No" buttons, because the order is different. Is there any way to set these consistently, either changing to the KDE order or to the GNOME order?
So I found out that this is not configurable within KDE Plasma. Here is the culprit:
QDialogButtonBox::KdeLayout is hard-coded in the source code as a style hint of the Qt5 intergration plugin. One way to change this is to patch plasma-intergration to use
Another option is to use qt5ct. If you set the theme to Breeze and set the following menu option to GNOME, things look and feel much like KDE.
However, since I'd like to stay as close to KDE behavior as possible in all respects but the dialog button layout, I didn't find this option satisfactory. Your best bet is to patch plasma-intergration. Maybe at some point it will be updated so that it's possible to set your preferred dialog button layout.