There is nothing doucy about this. I believe AA list this as a specific benefit. I go to the Priority line all the time if I get to the gate and they are on group 5 or greater. I am always noticed by the GA and taken. It may take the GA a few general boarding scans to notice you as they have their head down scanning boarding passes.
Now, it would be doucy to cut in front of Priority 1 - 4 boarders if their number was already called and you have a lower number.