Passing link state in L2 topology

Hey everyone, looking for some advice regarding a L2 customer aggregation project we’re working on. We recently bought some NCS 5001s to use in Satellite mode with our ASR 9Ks for the sole purpose of 1G customer aggregation. ASR9K would be all 10G ports, NCS all 1G with a bundle between the two. 10G customers would peer (BGP) directly to the ASR, 1G customers to the NCS in satellite mode (managed by the ASR). Turns out the NCS in satellite mode forces auto negotiation, and Cisco's solution is to "tell customers they must use auto negotiation " which is not a viable solution for us. So now we have NCS 5001 that we are trying to not have to RMA. Using the NCS as a standalone L3 device would be simple enough, although buying the licenses for this would be pretty expensive, as well as more work from a management / provisioning perspective. As such we are trying to come up with a L2 solution.

Where we keep getting stuck is how to pass link state from the NCS to the ASR, so that we can have BGP on the ASR shutdown due to the NCS port going down, vs needing to wait for the BGP hold-down timer to expire. The few things we've looked into (l2vpn w/ l2transport propagate remote-status, Static L2TPv3 Pseudowire, and q-in-q) all boil down to have the same problem of not being able to shut the sub-interface on the ASR side of the trunk when the remote side goes down. This could also be solved by using 1-1 port mapping between the ASR and 5001, but that would defeat the purpose of this port aggregation switch.

I am almost certain a technology is out there that will accomplish what we need, I just do not have enough experience to have run across this in the past. Wondering how you guys would tackle this problem if faced with the same situation. Let me know if I can clear anything up, thanks!