I dont have much to add except that you can get a Gryphon CS or CTS for your truck.
I had an 01 with a Gryphon and it never showed whether the TC was locked or not, I have never seen anything except a 1,2,3, or 4 in my gear selection box as well.
I did notice on my old truck that if I adjusted the WOT fueling the truck would run like crap, exactly how you are describing. I dont know if that is related to the same thing because I could adjust almost everything else and nothing would happen, but to be sure about things, if you really want anything like that adjusted I would get the Gryphon CS and have Bill do it for you. I know its not the answer you were hoping for, or one you could afford either lol, but Its my advice
. With your mods you dont necessarily need custom tunes, but they will always help, plus Bill's shifting strategies arent Edge's, so you might like them better from the start.
Hope I could help