I've been a slacker... I've had my ITB parts for months now and yet to install them. Well today I've started pulling the AE101 ITBs apart to clean and possibly paint. I also took the adapter plate to Chilton Engineering, can never recommend them enough, and had them check it over to make sure everything was flat. Unfortunately, the side that bolts to the head wasn't very flat at all. This was concerning because there are water outlet/inlets on that side of the head and I didn't want to risk water leaking into the intake.
Photos below of the amazing looking adapter and the re-surface that Chilton did for me.