LS3 vs LSA temps

[monstar]

I might be wrong but I was under the impression that on the LSA motors the PCM measures the IAT's pre and post blower. On a blown engine the IAT pre blower isn't really useful for much.

Yes IAT1 and IAT2. The MAF meters the (oxygen) mass of the air intake charge, it needs the temperature at that point to do that.
After throttle body, whether the charge is expanded or reduced in volume doesn’t affect its mass only volume, which affects pressure (boost).
Think air quality and boost, two different reasons to measure temp.
The GenV ECU also factors humidity from a much more advanced MAF.