OK I did it. I was in the neighborhood and had the G40 done. I also had them redo the G25. And that was the reason I went in. They did give me a little grief over running the UniChip and the super charger but the GM said just do it so I got the G25 flash, reflashed. Now hopefully my stall bug is fixed, again, that I didn't have to begin with.
I have noticed no significant change in braking at all. But admittedly I'm not sure what I'm looking for.