I don’t know if there’s an option for this somewhere, but I didn’t find it.
This feature is really essential for viewing picture books for me. Dual page view helps but if it was possible for a continuous horizontal scrolling of pages, that would be brilliant.
Thanks.
On a tablet you can workaround by rotate screen to horizontal then rotate pages to match so whole file is horizontal for flicking with menu under thumb on one side (it was even possible in old versions 3.2 and before to use a rotated menu bitmap) However using desktop and non-touch screen or mouse is a mental challenge.