ok, let me explain… (and yes, the one in my car is just a board… but it does have the holes drilled for the nails… just no nails!)
The Pin board is like a bed of nails. You put your workpiece on it to elevate it off the (dirty) grid and it keeps smoke from the burning gunk on the grid from getting on the backside of your workpiece. it also avoids laser reflections from the grid from causing “nicks” on the bottom side of your cut. (yes, that happens)
It ALSO can serve as a jig of sorts to hold oddly shaped items that tend to roll or don’t have a flat bottom opposite of the side you want to cut. (when you said Jig, I thought this might be what you are talking about)
Since the plywood of the pinboard is a couple of inches away from the focus point of the laser (the tip of the nails, usually) the board doesn’t suffer too much damage besides getting a little burned. After a while, we make a new one.
If you’re looking for something to be able to load work pieces repetitively in the same position, this isn’t it.
I just tape some thin strips of wood to the bed to use to position the piece in the same place every time.