@cryptix
No call notes on that. We didn't discuss specifics, only identified this as something that we'll encounter in the future. Piet maybe sooner than me, but I'll certainly chime in once this gets (re)discussed.

As for muxrpc, we want to replace it with bpmux. But the "calling feed id" sounds to me like an application-level concern, not a protocol-level one. Pretty sure we won't need to modify the protocol to implement this.

I designed muxrpc with the use case of an endpoint transparently forwarding messages in mind, so that's going to play pretty well with out-of-process plugins. For example, it allows heartbeats on a per-stream basis, which can be relayed to the responsible plugin, thus allowing plugins to hang without the system getting into an unstable state.