TSA doesn't care which line you are eligible to join, or how long it takes you to get to the checkpoint. All TSA does is carry out the screening itself. The people checking your ID are contractors working for the airlines. Thus, if you have concerns about which line you can use under which circumstances, contact your operating carrier.

In the scenario that you mentioned, I doubt that you would be allowed to enter the elite security line unless you also were an AA elite or were traveling on AA in first or business class.




In fact, under our current system, the selectee (SSSS) program is operated by the airlines as well. The airlines receive watch lists from various different agencies and make the determination (via computer) whether to "select" pax for secondary. TSA simply conducts the screening.