The current KDE Plasma OSDs take a lot of screen space, and espiecally considering the fade-in fade-out animation, they take far too long to hide. I am not opposed to the animation, but to the size. The OSDs are quite frankly, gigantic. I found this on the r/kde message board as to a user who had done some tweaking-

It would be cool if this were an option, to scale/change the OSD. Perhaps implement themable OSDs, or give the user the option to choose position + size?