i think its funny how anything possible on the passenger side is always bent, smashed, broken, or fell off haha
did some interwebing last night- i think if i make a bench harness with a working OBD, John can delete (or Patch the OS to accept VATS deletion) and then i should be good to roll with some transmission wire digging to "wake up" the 6l90 like i had to do on the last 2014 one.
worst case i can buy the latest HP tuners bluetooth module and get everything i need to do it my self for 350$
not a ton of info on 2015+ used for swaps but i found a few threads with some light of hope that its very possible.