Well, the welder screwed up his math and instead of increasing the diameter of the 12mm holes, he added an 8mm hole on each side. Beacuse 12+8=20, right? :P
Anyway, I decided to give it a shot and install it anyway. Here's the result.
https://www.youtube.com/watch?v=Q4-6uec4U_E
I quite like it. It's a bit louder, but not anywhere near obnoxious. And considering that the wife will drive it 300 miles on thursday, that's probably a good thing.
If I still want more, I can always add a couple of Crios holes as well.