This is a fun mockup I made based on your Propædia document. It’s a low priority feature request, but it would be really cool if when you moused over the outline ribbon area, a tooltip would pop up to show you the parent text. That way you could maintain your context in a very big outline.
You could also borrow features from code editors & IDEs that allow for “code folding.” If you click on the outline ribbon, it could collapse the parent bullet.
