In case you got two monitors identical in effective resolution and screen size, it could be rather useful two stretch Okular over both screens to generate some kind of `ultra wide` screen. By doing so it would be convenient if Okular displayed one page on one screen in the `Facing pages` view mode, i.e. the left page on the left screen and the right page on the right screen. Right now it simply stretches its UI over both screens, so that one page may end up partly on both screens. If it were possible for Okular to detect which part of the application is on the left and which is on the right, it would awesome to have such a feature. :)