you'd notice that the recirculated SSQVs work perfectly on a stock T system even with the 2.5" piping. The problem only occurs when you put on a dual pop. Which is the point of this post.
As I said, I have no idea why this occurs because the air is still metered and can only theorize it has to do with turbulence with the way the SSQV works but not bothered to find out.