As it says.

I love being able to make a construction or my research loadup first by alt then left clikcing the option, it makes it great for making priority on a newer planet, or being able to add to the list without taking away my last item(generally plant cracker lab).

The only place this doesn't seem to work is in system view when clicking on the buttons to terraform or add a planet specilization. I know its a tiny change but it would feel a lot smoother to be able to do the same thing that happens when you use it elsewhere.