[j-nsp] MX connectivity between Routing Instances

[OBrien, Will]

I'm working on a routing design that uses multiple routing instances to allow traffic shaping based on destination, CG Nat based on destination and a set of traffic filters.
Those three things don't tend to play very nicely together on the same interface since they're all require various firewall filters and even service filters.

Has anyone built any interesting routing instance configurations to accomplish this? Previously I was going to have a physical loop that ran through an IPS, which gave me an extra pair of physical interfaces to work with.
I've migrated that service elsewhere, so now I need to research how much I can do on logical tunnel interfaces.

Thoughts?