All I can do is speculate based on how my car "feels" but I think this really wouldnt be of practical benefit until 60-70mph, or the start of 3rd gear. 1st and 2nd gear disappear in 3.x seconds anyways and you're already in 3rd at that point so...
Just a nitty gritty detail. Depending on Terrys schedule next Month and how worth it this is to him and the xi crowd, I could probably get him my car to do this with. It obviously comes down to ROI for Terry. How many of us would actually pay for this if he were able to come up with a solution? What I'm asking I guess is will this be worth it for a) me to take the risk on my car b) him to invest the time?