I've tried it on three different race days. Ist day seemed to work well, didn't improve my ET at all, but cut 1.68 60' times with out tire spin.
Second day was the DPC and track prep was garbage. I was spinning hard even with second gear launching, but helped on my ET's that day, the tranny started shifting poorly by the third launch.
Third day, I was running two classes in 90 degree temps. After about the 6th pass, the converter would not unlock at the end of the track causing the truck to lug, smoke, and sputter. The converter finally unlocked with a bang and my tranny temps went into the 250 range. I was in the finals for both events, so I loaded a 1st gear tune back in and hotlapped the next two final rounds in first gear.
The second gear launch for me doesn't help ET on a good prepped track, but I can see how it would on a poorly prepped track.
2nd gear at my power level seems very hard on the 1057. I watch the logs and truck will launch at 2900 and stay in the 3200rpm range from 0-45mph. Tranny runs hotter. Shifts then seem to fall off.
My thoughts are, give it a shot if going for best ET, but if running in a event where you may be making multiple passes in quick order, I'll stick with 1st gear launches.