Really?
From what I've done, LSA has very little effect on idle. It's the intake closing that causes low speed issues.
If the intake valve is still open, and the port can't overcome the upward movement of the piston, you get reversion. That reversion is where you get the dead rich idle you can't clean up.
Ever check the speed of the air at low lifts? If so, you know that at low lifts, the equal flow bench depression can be 120 inches or more.
Now, if you want me to believe you have an over scavenge condition at overlap, I can discuss that. Again, this is why you have to pay attention to things OTHER that maxing out low lift flow. I know David Vizard would disagree with me, but we agree more than not.
You can kill more things with ridiculous low lift flow numbers than almost anything else. I mean, do you use a radius valve job on the intake valve? I promise the correct radius valve job will outflow a valve job with angles every day of the week and six times on Sunday. But it will be down on power. Why?
One more thought. Back in the day, I was dealing with a customer with stage 6 heads. Someone else worked on them and the car was a pig. The first thing I noticed was the intake bowl was contaminated with exhaust. Hmmmmmm.
LSA is the RESULT of cam timing events. As I have said more times that I care to type, you can alter the LSA a bit AFTER the correct timing is set. The other thing is INTAKE CENTER LINE. You can install a cam 4,6,8 degrees advanced and change the intake valve closing. This will alter the idle and vacuum. The concept is not difficult unless Comp has brainwashed your mind.
