Though where would you put them? On the side there isn't room unless you do a single-slot card or a particularly short card, and on the top it'd be 60mm fans at most.
I wonder if using different hole drills and just round perforations, one might even mimick the look of the shading on the cubes.
The problem is that these holes are now elliptical, so they couldn't be drilled or stamped.
But it does look extremely cool, I'll give you that.
Well done ! I tried to mimick it on a metal-color sidepanel to get a better grasp of how it looks: