I will save time by copying and pasting from the chat log, which I typed after the queue closed on this topic:
Martin Thomson: Unfortunately, I don't think that Ian's suggestion to use the first CID seqno on the path works. Martin Thomson: You need a shared understanding of what a "path" is in order to do that. Martin Thomson: What I think we want for path abandonment is "you are sending to me with CID seqno X, please stop" with an implied "and stop sending on that path" Martin Thomson: like STOP_SENDING, which asks the peer to send RESET_STREAM, you would say PLEASE_RETIRE_CID
