Instanciate several nodes with the same key
Currently, each node emits it peering document across the network with a single interface that is known by him.
But one might want to instanciate several nodes under the same key. The problem is, today each node with the shared key will only declare its own interface, erasing the one of the other node.
This lead to a never ending switch of interface behing the shared key.
A solution would be, given the fact each instance publishes an interface, that each node recognizes another node shares the key with him as it is receiving a the peering document containing this interface the local node did not write.
So the local node could test the remote interface for fact checking, and if the interface answers, to add the local interface to endpoint list instead of overwriting local interface.