Having worked in the service lanes of a Chevy dealer for a few years while I was edumucating myself, let me explain something on the warranty.
ANYTIME, I do mean ANYTIME you alter the vehicle beyond stock or add alterations that are not approved and/or installed by the dealer, you warranty can legitimately be voided. There are some dealers that are a$$holes and will follow the letter of the book, there are others more lenient and of course there were dealers like ours, that in most cases didn't care and that the modification had to be the sole cause for component failure.
Can your warranty be voided for doing your own tuning with LS1Edit? Absolutely. Just as you can read all the tables, parameters and other data on your laptop, they can too with their hand held scanner called a Tech2. Hence if you remove torque management, you run 500+ hp into it, then fry it, then go to the dealer and tell them your trans took a sh*t on you, one of the first things they look for is TM table manipulation. They know of programs such as LS1Edit, aftermarket tuners, HPPIII's, etc. They know people like to eliminate TM. If it is not set in a range of stock settings, they know you've tampered with it and justifiably will void your warranty. They may just deny warranty coverage on the claim or they could completly blacklist your VIN#. Once again that depends on the dealer though. So returning it to stock settins won't trip any red flags as such, they probably won't investigate any further
04GTO, transmissions aren't cheap. You go eliminate torque management on it so as to get full power during shifts with your heads and cammed LS1, 50 runs later at the drag strip the transmission pukes on you, and now GM has to cover it??? That's why they put it on there. They have some fo the most powerful engines in their vehicles that they now must warranty for 3yr/36k miles (or more) you can bet they're gonna protect a few vital, costly components where they can.
Trust me, I hate TM also, my Allison is worse than many 4L60/80E's. But I don't want to eliminate it, then have to foot the bill for an Allison transmission cause they make Hydramatic units look like chump change in terms of price.