It would seem that something like forward error correction would be even more effective/attractive in a wan router that already supports multiple wan connections and the bonding of those connections.
How about something just for VOIP and other interactive, packet loss/delay sensitive flows?
Imagine a scenario, for example, with a two Peplink routers, two bonded wan connections on each and VOIP traffic between the two via SpeedFusion. You could just double up the 64kbps (for example, potentially much less) stream and send it across both links. On the receiving end you just watch packet order and accept/pass the packet that arrives first (simplified, of course) the late packet gets dropped. Instantly able to absorb all sorts of packet loss and even varying jitter/latency/congestion levels. One wan connection down/slow/jittery/saturated? no problem. Call stays up, quality not impacted. (or at least much less so)
Just a thought. Seems like a killer app to me though.