A few months ago we ordered some cheap ABS cases from Aliexpress. I planned to replace the side inserts with laser-cut ones. But it turned out that the replacement was not so easy to produce 
Then I jumped into designing a vacuum table. My idea was to have a base (green) and different tops (blue) to hold the parts (red) in place.
The shop vac does not like its new job 
But milling a set takes about 2’. So it won’t overheat. At first I expected the parts to fly around the shop. But nothing happened: It just worked 
By the way: The whole vacuum table was milled with Kiri. Also the paths for milling the inserts are done with Kiri. Trace does a very good job there. Thanks @stewart 
More pictures: https://photos.app.goo.gl/ALzVuDLSCWnQbxCeA