Actually, I think I was making some assumptions without all the background. I think they'll tweak the throttle body adjustments, but not the actual map, too. We'll see how it turns out, and if it's not feeling right or my mileage drops to squat or if I break down in Gila Bend with fouled plugs (again) I'll probably go for the Power Commander. It doesn't have to be perfect, but should be at least as good as a carb setup.
I expect it will be OK to "adjust the trim." This is the 620 and we're replacing stock parts that flow OK on the (stock) 800, so I don't expect much benefit except on the top end anyway. Conversely, I don't expect to hole a piston on the way to the shop either.
Sorry about the fancy words, but if you don't use them, then you have to use three or four more to say the same thing. I did have to look up the spelling of "stoichiometric" though as I seldom have to write it.
-Don