I wanted to keep the 'Use Camera Matrix' as a checkbox and not a dropdown because my muscle memory is with the checkbox as I typically process 80 - 100 clips at a time once or sometimes twice a week so it adds up.
Why not do it just once, Ctrl+C, configure as in screenshot, Ctrl+A, Ctrl+V... and no matter how many clips you have, the camera matrix option of all clips is configured like the clip you edited.

@70MM13: thanks for you idea... I tried so much, I even tested another much more complicated implementation for Windows only... but I didn't got it better, nothing was working for me. Maybe I just did it wrong, but now we have a 99,9% identical implementation for 3 different platforms, 2 work perfectly, one works but is ugly.