dedicated spoilboard
You'll probably want to make a special spoilboard.
If there are bolt holes in the part, you can just program those first, and then put hold down screws into the spoilboard. This could be as simple as drywall screws into the MDF, or as elaborate as a special aluminum or plastic fixture with threaded holes.
If production needs were higher, you could build a special vacuum fixture with channels for gaskets cut inside the perimeter, and around all the holes and cutouts. This can work with a very small vacuum pump.
-Jim Hart
My main machine: Multicam MG series (MG101) with original Extratech H971 controller, Minarik servo motors, Electro-Craft BRU-series drives, 4KW Colombo. Let's talk Multicam!