Man, great ideas here, Donna Teuber Riffing on your post for a minute - Choice and Delivery Method both seem underrepresented by the current conference. Parents get little control over the day of P/T meetings (teacher's don't either). Students are usually talked about rather than talked with (a critical failure). And parents must "pick up" the input from the teachers at very specific locations and times.
Theoretically, better communication throughout the school year could simplify the number of activities crammed into a P/T conference. But there's so much value to the "face to face" conversation, and many of us just won't do it unless someone makes us.
I wonder if P/T events could be scheduled more like a food court (to use your analogy), offering concurrent types of meetings - stand up (10min), checkins (a couple minutes), group discussions, short talks on common topics ("helping with homework vs short-circuiting learning"). And perhaps rewards for those who engage more deeply.