I've never heard of shadow foam before, but will check it out. I attempted something similar a while back with my Switch using this packaging foam and a scalpel. Had a smart flight case for it to sit inside as well.
The cut out I made wasn't as clean as I had hoped tbh, it was functional, but not smart enough for my liking.
Maybe it's something I'll revisit in the future using this stuff.
@GtBFilms I left in as much as the cardboard filler inside as I could to help in not slide while still letting the cables get where they needed to.
We cut it so close to the screen dimentions that overall it's a very snug fit. I suppose if you were really worried about it sliding around you could drill holes in the bottom of the table to match those found on the back of the monitor where I removed the mounting plate piece. Then it would just be screwed into place. Another alternative would be to put blocks in place on the table that prevent the screen from sliding rather than relying on the cardboard. So far I havent had any problems though