Not doubting you, but looking on
ACDelco's site, their wording makes it sound like you can only program every module once over the 2 year period. If you only program one or two modules, maybe you can do them multiple times till you hit the total number of modules you have... Any clarification?
you can update whatever want as many times as you want the only catch is, once it is updated there is nothing more to update unless they release a new calibration (within that 2yrs), if you want to replace the abs module 500 times you can.
you can sit there and update it over and over all day long if you wanted to be a nerd it will just tell you that you already have the latest calibration.
once you pay for that vin slot you can go willy nilly on that vin, if you want to program another vehicle you have to pay for that vin also (another $45)
the bottom line here is you will probably only use it once to update it or replace a module then you probably won't ever use it again unless something happens to fail within your 2yr period.
once your generation of vehicle is finished there is unlikely to be any future new calibrations unless there is a recall, gm doesn't sit there and waste money making new calibrations, once there done there done, they move on to the next generation, unless like i said a recall is discovered or some major fix in which case there would be a tsb with a new calibration, but those are rare once the warranty is over.
the first time you scan it with the software it's going to show all the available updated calibrations which might be 2 or 3, then you can check them or uncheck them, do the updates and your done.
my guess is you might see 1 for the cluster, 1 for the radio (most bus), 1 for the transmission, anything else is going to be random, maybe ecm.
the brake software was under recall so that should already be done by the dealer a good while ago