2016 Chevy Silverado 2500HD 6.0 gas 135k miles. I added 35" tires and used the Gear/Tire wizard to adjust my speedo and it ended up also adjusting my shift points. I also disabled TCC. (tune is attached)

Is this normal? Are the speeds the transmission sees not from the re-calibrated speed sensor? Seems to me that correcting the speedo would give the transmission corrected speeds and no need to really adjust the shift schedule.

Recently while towing a big pontoon boat through mountains, the shifting was just plain annoying. The truck was both lugging/bogging down and then overrevving when it down shifted. It was in tow mode and I didn't have the thought to try not being in tow mode.

2016 Silverado 2500HD v5 Add TCC disabling.hpt

I didn't get any logs either. Next time I do it, I'll do some logging. Any suggestions for particular values to log/watch? Speed, Throttle, Gear, TCC slip, line pressure, etc...?