Custom made pan stiffener. There are some available through a couple outlets, but those usually just bolt to the pan and a single clamp around the lower beam. They are supposed to help reduce the overall chassis flex by adding another brace point.
Dunno. I haven't seen them used on too many cars and the adverts specify "for racing or off-road use". I think a solid bar from the perimeter frame to the front beam would be "better" for stiffening rather than relying on the floor pan steelmetal... but that's just me