Again without PCM OBD data its hard to guess.
It might be a IAC issue or simply your looking at this with too much depth since PCM only reacts to LTFTs once every 10 minutes and at the time these changes are seen is the PCM is in "fuel learn OFF" and if that is the case no matter what the values are they are being ignored and not added to the fuel trims averages.

As too MAF being too hot that should not effect those exposed sensors since it is measuring the mass.
The new MAF used in the C6 Z06 does not even have a MAF case, it is just the electroncs stuck into the airbridge.

Check airflow tables to decel, park and idle for anything weird or even timing values at the moments before and after this issue is seen and what the grams/cyl are.
Also still suspect is any bleedoff/popoff valve and also where its located