it's probably a combination of both. All caps are managed by the AAA systems so to link the systems with the routers are quite challenging if not impossible with current technology. so a blanket rule would be the most straightforward.

i think tm can and has already implemented a mechanism to differentiate classes of internet users at their international gateways so in a way this would address the issue. local traffic would probably never be subjected to congestion provided the local backhaul are overprovisioned.