When you add attachments to the plate carrier it always changes its durability to damaged, even if the attachments themselves are worn or pristine.
also, as a side note. the pouches currently take up so much room no bag in the game can hold them, is it possible to have the plate carrier pouches consume 2x2 slots instead of 3x5 when they hold no items, this would allow players to carry them in a backpack in hopes of finding a plate carrier to attach them to.