Is there aisle width to get past the seating? And the post becomes a bigger issue.
I lean towards a wider, slightly deeper version of your first version and recess the screen into that alcove area. It keeps that pesky post in the back of the room, at least out of eyesight. And maybe that post could get buried in a back wall that reflects the front wall. If you want the equipment closet, it could be added to the bottom wall, since you have lots of room to play with in that direction.
Is there any plans for the 9' wide space at the bottom of the stairs? The av rack could go there.