[erketre]

Originally Posted by kovidgoyal

Of course you do, just google FOST https://en.wikipedia.org/wiki/Flash_of_unstyled_content

So? From this link you gave we know it is a known problem. But again; I see no broken paragraphs when resizing browser's window, nor font jumping form default to customized (for a fraction of second), as I see in new Calibre viewer.