2015 Malibu 2.0T module swapping

Figured maybe someone here might have an answer to my question related to swapping modules in a 2015 Malibu. My wifes Malibu's transmission decided to roast itself this morning - no motion in any direction, even when I tried to command higher gears, so in will be going a 'junkyard' unit with about 30k miles. The question is, in my experience, there is security in various modules that seems to marry them to the vehicle for good, which can't be changed - I know the HVAC module I installed from a scrap yard is throwing a mismatch DTC, but it's not causing any issues. But the TCM is a much more critical device, and if such security is in place with the ECM/TCM/BCM, that could cause issues. I know in my truck, being a 2004/2006 mutt, I can swap TCMs all day every day and it wouldn't give a hoot, but with the Malibu, is there security in place that permanently 'marries' the TCM/ECM/other module to the car in a way that it will cause issues? Is there a way to 'divorce' a module and 're-marry' it to the new vehicle? Or will I need to swap the TCM/VB that's original to the car into the replacement transmission?

I'm pretty sure the TCM (well whole trans + TCM + VB) will swap in no problem, it would be worth changing the VIN to match your car just to be correct but other than that I don't think the TCM is married to a vehicle like the ECM is.

So I've done a bunch of reading and I found a techlink article from Feb 2010 that states that the TCM/TECHM is NOT a part of the 'Global Architecture' security. But I've also read sources that say you CAN'T swap the TCM/TECHM between vehicles... I've also 'Discovered' that while SPS apparently won't change the VIN on a TECHM/TCM (or any other module, it seems), EFILive has no issue doing so (I knew EFILIve could usually change VINs of course, but the water has been a bit murky about what can and can't be done with newer controllers). And after changing the VIN on the 'new' TCM, I was able to flash the tune from the original TCM/TECHM to the 'new' one. So my question is, what exactly does EFILive read from the T43 (Which is apparently what makes up the TCM portion of the TECHM)? Is it everything top to bottom, and then in a full flash, it flashes everything top to bottom, or are there 'inaccessible' areas like with the LMM and LBZ ECMs?

Edit: let me clarify my question: IF there was an 'environment ID' and/or 'Immobilizer ID' stored in the TCM, would that data be read and then flashed into the destination TCM with a full flash?

Any controller that EFILive is able to read using our own processes (ie, anything but Bosch) we read the flash from start to end, the whole lot.
When writing back though we only write what is needed for the purpose, calibration only gets that area written and same for the OS. Exactly the same as what TIS is doing, the area that stores the VIN etc is not erased or written to by EFILive or TIS.