And that is the root behind the frustration with unimplemented feature requests. What to you is just a simple non-trivial addition, actually requires far more hours of work. Not only that, but then you add on testing, bug fixing, porting across platforms, and integration into the current UX, and what you thought would take a day is actually months of work.
Of course, if you want it to be graceful, fit in with the current scheme, and have more than just a text list (list sorting, collapsing/expanding multiple nodes, etc.) then you need to add extra time for that, too. Otherwise, all you get is a hack that only partially works, and can sink your product like a lead anchor.
Remember, if it was trivial and simple, it'd already be there. But good software doesn't happen simply by force of will.
(No, I am not a developer of this software. However, I have developed software, both individually and as part of a larger organization. I am not trying to minimize your request—a feature I too want—but merely trying to explain that your simple request is anything but, and requires much more work and effort than seen on the surface. Everyone wants their own features implemented, and everyone thinks it's a simple affair. The truth is far more involved.)