Originally Posted by
NYC Flyer
An agent definitely cannot override those restrictions, but they can combine a main cabin fare one way and a Premium Select fare the other using lower round-trip fare components rather than one-way fares. I suspect that would be the lowest cost option.
But the website already lets you combine main cabin and PE fares (in either direction) and will give you roundtrip fares. You don't actually have to go through an agent for such combinations.