Can I reuse a used TCM?

So I have an 08 Outlook with around 225k miles and was having some shifting problems and decided to replace the transmission with a used one. I found a used one from a Traverse with the same part code and started the removal procedure but when I opened the TCM on the old trans, I found three of the pressure switch screens to be broken. I swapped the TCMs instead of swapping the trans and took it to the dealer to reprogram the "new" used Traverse TCM and they are telling me that they can't clear it and reprogram it.

Here are my questions: 1 - Is it possible to clear and reprogram a used TCM and the dealer just doesn't know how?
2 - Does the used TCM need to be programmed or will it work if it's off the same model trans but different model vehicle?

I can order a rebuild kit and go that route with the old TCM and hope that fixes it but I'd like to change the unit if possible. Thanks in advance.