HI there,
I want to correct some misinformation we gave you earlier in this thread - we do in fact use the IDFA in the IMA SDK. Unfortunately I can't tell you which boxes to check, but I can tell you how we use IDFA. We simply grab the IDFA from the device and send it to the ad server. What the ad server does with it depends on which ad server you're using. For further info on that, you can reach out to a rep from your server (DFP, AdSense, Ad Exchange, etc.).
Thanks,
Shawn Busolits
IMA SDK Team