How is it possible to create GUI components that are similar to the Simulation Addin as described below?

When a new study is created using the Simulation Addin, a new tab is added to the model view. When this tab is selected, the model view stays the same (with some possible graphical modifications to it showing the simulation features) and a new view/control is added at the bottom of the feature manager view showing a tree.

Adding a tab can be done using the DisplayWindowFromHandle Method of IModelViewManager but that has to take in a control and it will either show the control full screen (replacing the model view) or at the bottom splitting the whole window (as with the Motion Study) - this is controlled using the splitwindow boolean parameter. There doesn't seem to be an option to not show the control at all (or not have a control, just a tab) or to have the tab shown just under the feature manager view as is the case of the simulation addin's study.

Any idea how this kind of GUI functionality can be done using the API?