I'm using the current F27 beta, enabled fractional scaling like described here
and set my monitor to 150%. GTK3 applications work fine including epiphany and libreoffice. Non-GTK3-applications are scaled up and get a blurry interface, including chrome/chromium, the mother of GTK “The GIMP” (GTK2), inkscape (GTK2), VLC (Qt) and, to my astonishment, firefox. firefox is based on GTK3 since its Version 46.0 (see ReleaseNotes
Question: Does anyone know, how I can get firefox to look as nice as epiphany with fractional scaling on 150%?
I would be fine with disabling the scaling for a particular window-class or similar and scale ff up with layout.css.devPixelsPerPx. This setting would also be interesting for applications to connect to remote-desktops which have their own scaling.