Sorry but it has to be said. The program is completely unconfigurable. I always have to install okular instead because the default settings which cannot be changed are just unnatural and not user friendly at all.
For example if you open a pdf it always defaults to page width as the size. This makes the pdf document massive and so zoomed in its nuts. You can change the zoom to something else but since there are no preferences you can set for the program, if you go and open another pdf it defaults back to this ultra zoomed in experience. It genuinely makes me angry even thinking about it. I hate bad design. I feel like some basic configurable preferences would make the default document viewer about a million times better. I would love to be able to just open a pdf at a reasonable size by default instead of wanting to gnaw my own fist off in frustration at being visually assaulted by a pdf viewer.
Love you all. Follow your dreams. Believe in yourself.