I am on my 4th version of insert in the intake. You just need to get the air in the ports and not floating around in the plenum.To me it wasnt all about quickest ET. It was getting the air/fuel to the ports the same each pass for NSS index racing.
The biggest gain was a plenum spacer. I found that a 1inch plenum spacer worked the best for my combo.
If it is a "max wedge port" opening done by Indy... there is plenty to gain by working that as well.
I know folks dont like the modman. It works for me.