@Spencer Mimosa's architecture is Layer 2 from the Access Point through the CPE. All the termination functions (PPPoE/Routing/NAT, etc.) should happen on the gateway. We do this to keep the cost down of our high performance CPE. In a typical PPPoE deployment, if the customer bypasses the PPOoE termination point they won't have a method to get an authenticated, routable IP address and possibly will be blocked by L2 filters as mentioned by @Richard3.
To help assist with the management of the gateway device behind the CPE, Mimosa is developing several network integration features: