Qt::AA_EnableHighDpiScaling ruins font (/application) when DPR = 1.

AA_EnableHighDpiScalingThe font can get way too small on dual system screens when DPR is 1.
Steps to reproduce:

1) Have a 2 screen system with a 4K High DPI primary screen (that will get DPR=2) and another screen with a lower resolution (maybe just set lower) that will will have DPR=1.

2) Run the attached example and notice that the dialog looks good on the 4K screen, but nearly useless on the DPR = 1 screen.

Illustration:

Compare Window to a native Windows Explorer

This issue seems to effect Qt Creator. Furthermore the whole point in AA_EnableHighDpiScaling should be that it knows to scale on High DPI screens, but still can make the dialog look ok when DPR = 1 (and not require that the primary screen is the one with DPR 1 which would be unnatural).

Picture of the two screens (+ Qt Creator):