Strange Gen 2 Coyote Control Pack Issues (MAP, EQ Cmd, etc)

[S-351R]

Got a stock 2016 Mustang GT engine in a kit car using the FRPP Gen 2 Control Pack (harness and PCM). Return style fuel system, kit style mid length headers (O2s not too far from a stock shorty) , and K&N CAI tube.

Tune very stock, but accounts for Return system fueling, and a few off-road / kit car disables. MAF Trims for CAI are pulling ~-10 to -15% but MAF tube size is same as stock. I can change once I have more confidence I'm not chasing something else.

Issue 1: IAT is bad and reads -15F (4.54V), will replace integrated MAF Sensor unit, correct?

Issue 2: At KOEO, Calculated MAP reads about 85kpa and MAP SAE reads 100kpa. At WOT both MAPs read same and start at about 86kpa and drop to 83kpa by end of pull. Suggests something limiting airflow in creating vacuum at WOT, but surprised to see Cal MAP read low at KOEA.

Issue 3: With stock GT parameters Enabled, we are getting codes for IMRC Stuck Open in both banks. Can troubleshoot this, but how likely is this tied to the above MAP airflow issue?

Issue 4: WBs never really work very hard to correct to EQ Commanded even when trims are <15% and there is plenty of time elapsed.

Issue 5: Related, EQ Commanded never goes into PE at WOT (.95-.96 Lam) even when every other channel shows good WOT or OP status. WBs go to .80 Lam but external sensor at tailpipe shows .95 consistently at WOT. And at idle commands 1.27 Lam (?!) It is a very hard start, but idle generally ok.

Sorry for all the issues, and just hoping someone can tell me if somehow they are related to a singular cause or parameter, or best way to go about troubleshooting.

Many thanks!