I recommend the IAT sensor being before the boost and close to outside weather because it stays fairly constant.

Reason GM startng with 85 mm MAF included the IAT in it rather then older versions IAT was in the airbridge

With boost heating the air up and PCM seeing that causing surging as boost flows ramps up and down and then several tables in the PCM adjust and take into account what IAT is since its assumed the hotter the air is the worse the quality of cylinder charge and pinging so that had to monitor and adjust to limit this by pulling timing and increasing fuel flow so you do not want PCM to be getting hotter IAT all the time.

The maggie supercharger tended to fool the PCM to go rich as they install IAT right into the intake manifold and you see that with more surging with that design