The diablosport tuner I got has transmission shift point tuning. I can't speak for any older units, but this unit does turn off DoD as well. It's worth a shot as I can use it for other things as well.
Edit: I got the tuner they sell with the kit.
Pricing Update! Due to manufacturer price inflation, our AFM kits will be increasing in Jan 2025. This kit includes everything needed to delete AFM/DOD (Active Fuel Management) from 2007 - 2013 GM 5.3L truck/suv engines. Kit includes a Diablosport Handheld tuner capable of turning off AFM/DOD...
www.amsracing.net
I've read that it actually just installs a stock tune with DoD disabled on the diablosport forums.