Only in Tampa Airport one time, although wearing your TWIC card in a necklace might get you airport employee discounts. It has for me.
The TSA Pre-Check, as another poster put it, assigns you a KTN. But that KTN has to be disclosed to your airline before they cut your boarding pass. If you have a valid KTN, they will print “TSA Pre-Check” on your boarding pass, and THAT’S what the TSA schlub is looking at and for.
Given that most of us have tickets issued by contracted travel agents that don’t know us from Adam or Eve, Try to inform the agency of your KTN or barring that, definitely tell the airline people that when you check in at the front desk.
Just generally speaking, you get more mileage from people if you’re wearing your TWIC and Global Entry card in a badge holder. They might not know WHAT you are, but they think they know WHO you are, and being badge wearers themselves, they give you a smidge of professional courtesy.