opensuse 42.3 kde apps 18.04 kde framework 5.45 plasma 5.12.4 qt 5.10 switching scaling to 1.2 or 1.1 there is no problem with gtk apps as Firefox, Gkrellm but there is a problem with virtualbox (qt app ?): all is blurry for the invited os: text, icons. all which is a draw. i didn't made experiment with opensuse 15 but i think there is the same problem if someone installs virtualbox and launches an invited OS.