> communicate with people who are both on and off the mainline internet seamlessly.

I feel like trying to do that at the protocol level might be the wrong level of abstraction. Different fabrics have very different properties. Seems like the app is the more appropriate level for seamlessly communicating via different fabrics.

Like if I try to send a video to someone but they're currently only visible to me via lora the software probably shouldn't try to push a huge blob of data over that particular medium. But I probably do want the option of sending and receiving large blobs in general, just restricted to high bandwidth connections.