I keep one ASEK Strap cutter on my field gear and another in my car.
This tool was designed for aircrew to remove harnesses and cut shroud lines. A well executed piece of rescue gear.
Non-threatening, TSA-approved and it works.
Well suited to removing heavy gear, including body armor, or seat belts. Cutting t-shirts takes a bit of care, but uniforms, webbing and heavy nylon duck can be sliced easily. Be sure you train with it and that your partners train with it as well. Keep the EMT shears because everyone know how a pair of scissors works.