browser.display.use_document_fonts is Settings → Fonts → Advanced → Allow pages to choose their own fonts, instead of your selections above. Note that that’s di

browser.display.use_document_fonts is Settings → Fonts → Advanced → Allow pages to choose their own fonts, instead of your selections above. Note that that’s distinct from disabling web fonts: it will cause your chosen fonts to be used (so `font-face: some-web-font, Arial, sans-serif` will resolve to sans-serif), but still allow loading of web fonts for the Private Use Area, so that all mainstream icon fonts except for Google’s misbegotten Material Icons (which uses ligation of ASCII code points, which is a technique that was a horribly misguided idea from the start and makes accessibility worse far, far more often than it makes it better, and the precious few cases it makes better could readily be made betterer by other techniques) will still work.