Interesting, this is highly reminiscent of the boarding zoo on CX flights, especially elite-heavy long-hauls like JFK-HKG. It's kind of absurd when J/F pax, elites (MPC SL/GO/DM/DM+), AND non-elites (GR), are indiscriminately lumped into the priority boarding lane. As one paid F customer behind me once put it, "What's the point of the regular line??"
Yet, despite all that chaos and children/handicapped boarding before priority pax, CX consistently manages to board a 777-300ER within 30-45 minutes. Granted this experience comes on a different non-US carrier, but still, maybe non-zone boarding might not be that bad?