The snippet in this post would make for good core functionality. You could load a page include from anywhere on the screen. It would allow you to create a tabset without having to have the structure of a tabset or a tab list displayed. You could use a nav button in your header to dynamically load content that makes up the entire right half of your screen, for example. With the nav or button you could pick your page include and load in parameters as needed. A load inline frame template action is also desirable for content you may want to load outside of salesforce on a third party secure site as an inline frame. https://community.skuid.com/t/change-the-page-included-in-javascript