Application with Qt::AA_EnableHighDpiScaling and dpiawareness=2 seems to round scale factor to nearest integer. For example, 125% is same as 100% and 150% is same as 200%.
With native applications, like notepad, each scaling factor seems to scale everything (menus and content). In Qt applications, only window title seems to be affected when switching between 100% and 125%.
It seems to work fine with dpiawareness=1.