Trans swap - GenIV pcm T42 question

I'm considering swapping a 4cyl Ecotec engine into an older car but would like to run a 4L60E behind it rather than the 4T45 FWD or 5L40 transmissions they use in the stock application. The reason for this is I need a rwd trans, and to my knowledge nobody has tuning support for the 5L40 trans at this time.

Is it possible to run a engine/transmission combination other than that offered in a stock application?

I'm familiar with doing a trans segment swap with the Gen III pcms and that the OS has to match to do so. Is there a similar compatibility issue with Gen IV pcms and T42 modules that would prevent me from doing this?