Thanks for the response Rebecca. I guess I am even more confused now.
I had written an email to our lawyer (this is not our original dimwit lawyer) asking her about the POE's and the temp EAD stamp (along with the TB skin test stuff). Anyway, this was her response to me:
Some ports of entry will stamp employment authorized on the I-94 upon entry. For those that don't, our local USCIS office will stamp the I-94--he will simply make an InfoPass appointment and take his passport to the local office for the stamping. As you note, the problem is that the employment authorization expires when the I-94 does, in 90 days. He will have to apply for work authorization when he applies for AOS after the marriage, and it takes up to 90 days to get the EAD after application. Therefore, a gap in employment authorization is likely, if not inevitable. His will have to find an employer who understands and permits the leave period during that gap.
Maybe I should check directly with the local USCIS? Or perhaps I am misunderstanding what she means here????