It’s an easy way to route tb/shout/bandmic/… to your listen wedge / Iem. so you cann hear them all the time no matter what you are Pafling. And yes i know there is a “EXT in to pafl”. 🙂
Also it’s a very handy way when a musician’s iem system breaks down and you dont have a spare, you just route his aux mix to this matrix and give him your beltpack. ( You then have to unroute the pafl and other stuff you send to the matrix offcourse).