Sometimes it is convenient the twin command responses to be sent to a destination, different from the source connection, where the commands orginated from.
The destination could be defined in a target of a separate (maybe dedicated) connection, in which the address and header mapping configuration of responses should be placed.

Implementation proposal:
In OutboundMappingProcessorActor of the source connection, the outbound messages (responses) could be diverted (or not, depending on the source configuration) to the target connection OutboundMappingProcessorActor by sending a pubSub message at a specialized for this purpose topic. OutboundMappingProcessorActor of the target connection should be subscribed to listen to messages on this topic and continue the flow with received messages.