I've also changed the way I'm making the vacuum boxes. I had to modify my process for vacuuming one sheet of film over top of another sheet of film, with the vacuum sucking each of them down individually. This involved routing a vacuum channel around the outside of the work area, applying the first layer of film over top and turning on the vacuum, then using the machine to punch holes at intervals around the channel in order to pass the vacuum to the second sheet. So since each different job requires a different channel pattern, I had to rebuild the vacuum boxes with removable top surfaces. It turns out you really don't need anything but a screw in each corner, since the vacuum itself will suck the board down and hardboard lays pretty flat on its own anyway.
So when rebuilding the vacuum boxes, I just cut the support strips and then grouped them all together and cut notches through all of them at once with a dado blade. The boards were arranged into two staggered groups so that the notches would be staggered like you see in the image. The boards were then glued to the table one at a time using weights to hold them flat till the glue dried. I could glue two or three strips a day like this and get a whole panel done by the end of the week. This was much faster than the way I was building vacuum boxes initially, and the resulting table surface is more level as well.