For large eSpaces with lots of actions / screens / ..., it would be awesome if by typing a few characters I could trim the tree into only some relevant items. A real time saver.
Another option would be to create a set of quick bookmarks (similar to those in Visual Studio or "marks" in VIM. There are many times when you're focusing on 2~3 screens and 3~4 actions so it would be very nice if there was a method of jumping from one to another in my current "working set" without having to scroll throughout everything I don't want to see right now.