Let me start by saying that I am a total newbie and do not do my own tuning or trans tuning. I do not own HPT. My car is an '11 V, I'm fairly new to the platform as I've owned it a hair over a year. Had a few other LS-powered cars (5th gen SS, TBSS, 06 Silvy), definitely not new to cars.
Recently, my V underwent some surgery. Normal bolt ons 582rwhp/627rwtq. No portwork and stock cam. The main restriction was heat.
Anyway, despite the numbers, I haven't been too excited about the car in general due to the trans tune. The car has about 33k on it, also.
When I picked the car up, it was set up with a safe tune and I drove it to the dyno to get tuned. Drove it home, and was still getting used to the new setup. Fast forward about 500 miles and I confirm that the shifts are flashing between 2-3 and 3-4. All of the other shifts are great. It's also ONLY doing this when in sport mode.
I asked the tuner about this, he said he loaded a trans tune from another car that had it (the trans tune was done by Fasterproms). He said it happened before on that car, and they disconnected the battery for 6ish hours. (Had issues with a fast relearn previously) Took the car out, manually shifted the car in many different scenarios, and the flashing went away.
I tried this procedure, the shifts got a little better at WOT and at times it shifted perfectly in sport mode. In regular mode it shifts just fine at WOT and moderate shifting. Not happy it, I asked him to go back to stock. It was reflashed but now I need to do the relearn (again) and see if the flashing is indeed cleared up.
I have heard of others in the V/SS/G8/ZL1 community talk about having to relearn their shift points, but I can't seem to find much detail on it. I found this site, I'm just looking for education and advice ($100 worth of advice lol). I have been lurking a bit and just want to cover the basics before something bad happens.
Is this battery disconnect and manual relearn the proper way to do things? Am I putting my trans at risk doing this? I'm not in a position to throw more money at a custom tune right now, but I figured that is my only option.