Though I hesitate to disagree with aeh, and in your shoes I'd trust aeh more than I'd trust saharafrog - I would seriously consider getting an IQ test done before you push for the skip. I think the school would balk at this item being missing from an IAS assessment. While I am not up-to-date on the 3rd edition's view on IQ, in the 2nd edition I'm pretty sure if you did not score above a certain threshold, acceleration was not recommended. I think the school could plausibly argue that a missing score is not above that threshold.
As aeh said, once all the elements are in place the IAS committee assessment can be surprisingly short. For both of my DD's accelerations, the IAS committees met only once and neither meeting took more than an hour. They really could have taken much less time, but we all wanted to make sure a thorough discussion took place.
Best of luck,
--S.F.
