I believe a significant number of people who have AMPRNet addresses and are BGP-connected really don't care much about communicating with other IPIP mesh-connected hosts; their interest is the rest of the Internet.
Of course traffic mostly tends to be local and we see some IPIP mesh traffic to stations in the area that are IPIP mesh connected, including country networks like Germany. Most traffic is between AMPRnet addresses connected on radio or VPN, and between those and internet.
It is understandable, because many IPIP mesh stations are small islands at the other side of the world and there is little chance that someone here would want to send a lot of data to them. On the other hand, connections internal to our network are used to interconnect repeaters (both voice and ATV) and for things like echolink and they transport a lot of data, mostly local.
Since there's no way to capture flow data for these folks, we'll never know where their traffic is going. All we can do is guess from anecdotal data.
Maybe we can setup some ip flow export...
Rob