The reason to hide a page in any given device, whether that device is hidden or not, is to prevent the page up and page down special actions from cycling through said pages. As with hidden devices, you then can only access a given hidden page via a page jump from another button.

In my configuration file all devices are hidden. All pages are hidden within each device as well. The only exceptions to this are my DIRECTV channel icon pages, my DVD cover image pages, and my Device Gallery. Within each respective device those are the only pages I want one to be able to page up and down through freely in the remote. All other pages of my configuration file are controlled by page jumps.

-Lowpro