Gnome/DConf text-scaling-factor affects QtCreator

If I set QT_SCALE_FACTOR to 2, the latest Qt Creator (4.1.0) renders beautifully on my 4K 15.6 inch laptop screen (via VirtualBox). But I also use some Gnome apps, so I set org.gnome.desktop.interface text-scaling-factor to 2.0 to get them to render at a readable size. But this seems to mess with text rendering in Qt Creator.

Please see the 2 attached screenshots for examples.

Is there any way to avoid this problem?

My understanding is that Qt >5.6 apps shouldn't really be affected by these DConf settings, but I guess it's an underlying problem with how stuff is rendered, beyond my understanding of it.