This has nothing to do with when it shifts, it keep the computer from pulling back the fuel during a boosted launch an between shifts..
I have an 03 with the 48RE and cant do a boosted launch with out it turned off.
You also do not need TNT-R for this feature........
down load the newest version TNT off the mads site for the s-06 and let me know where it is!!!!
it may have been there ( but not any more)*bdh*