Update on this: rebuilt the 6l80 with a new pump, clutches, sonnax billet piston, zip kit, and billet housing TC. Also got a hptune that adjusted some shift timings/pressure, deactivated DOD, and TC now only locks up in 5/6 instead of all gears. I also installed a tru-cool 40k cooler as I didn't have a way to flush the factory one.
Truck drives superb and hopefully will never have to go down this road again.