I did some pulls a while back before and after doing my UDP and found a couple things.
The first was that (at least with my Bluetooth odbii reader) I was only getting updates once a second, useless for counting time to make pulls from x rpm to y rpm. I then used durametric which can read many times a second. Still not conclusive, probably due to many factors, grade of road, temp, and who knows what else
still felt more powerful.
I think your idea of measuring a specific metric like air flow at WOT has a better chance fir a meaningful result. Or if you were able to do multiple before and after runs on the same day, same temps, etc.
There is a good thread on rennlist somewhere about doing pulls with a durametric that may be helpful and I will try. They focused on pulls in 3rd which did not get a person too high into the triple digits.
Good luck and looking forward to reading more.
I have got a cold air intake I picked up with a trailer I bought, while unsure of the various benefits it does come with the makings of a new intake tube that may be useful to folks doing this mod, look for it in the for sale in the next week or two.