Hello,
If I change the setting in System Settings -> Display and Monitor -> Scale screen (or something like that, my desktop is in Italian), I can get the UI to scale to fit my HiDPI monitor, but this somehow scales (zooms) the display in Virtualbox too. This is inconvenient as Virtualbox has its own scaling function which is more flexible.
How can I avoid this? Is there a variable with which I can start Virtualbox to stop it from being resized?