2012 6L80e Back-Date With 2009 T43?

[OEMOBDII]

Hi all. Have done some deep diving, and mostly come up with the same story, but there was one exception, so now my confidence is dented.

I have a good buy lined up on a 2012 6L80e 4x4 trans, but I want to adapt it into my 2009 Colorado (factory V8/E67). I understand there is a communication protocol change GM made in 2010/11 with the T43, so there is strong advice to simply match the year, therefore I should be targeting a 2009 6L80e and be done with it. I can get the 2012 6L80e for $650, and a used 2009 T43 for $100. A 2009 6L80e is otherwise $1000 and up.

I did find one article saying there was a corresponding change made to the valve body at the same time, so now I am confused if you can simply put a 2009 T43 into a 2012 6L80e, or not. I think so, but now not certain.

I do have full access to GM MDI tools and subscription, if I am able to back-date the included 2012 T43 to 2009 operating system, but I think even with the proper GM tool this is unable to be done? Or, is that only the case with aftermarket re-flash programs such a EFI-L and HPT?

End question becomes, will a 2009 T43 fit and work in a 2012 6L80e?

Thank you in advance. If I missed a similar article, apology.

[OEMOBDII]

Another possibility would be to uprate my 2009 Colorado E67 to 2012 operating system, and then not have to change anything regarding the T43? Or am I on the wrong path entirely with that?

[Tre-Cool]

I've read that changing the vin on the ecu to match the year on the t43 can fix any issues. a member on the efi forum who does retro kit installs tested it out with a car that wouldnt get reverse. he was able to use 07/08 e38 with 2012 tcm's.