I continued my stumbling experimenting further, now with nodes kindly shared by @gregorius
In my nearby, local RPi, I have a flow that can send a request to a remote RPi to get the complete flow returned. Communication between the both is via a public MQTT cloud service (HiveMQ)
The returned flow is saved to disk. Then being imported for some editing, then exported to a another file, finally sent to the remote, again via MQTT
My local RPi
When the flow is arrived at the remote site, it is replacing the current flow
My remote RPi
So far so good. It seems to work. But I have to be careful, it is easy to damage the security setting of the MQTT broker since credentials are not transferred
Ideally I really would like to avoid updating the flow tab with the MQTT nodes, I would like to just leave them as is but I cannot select which tabs to send, only the full flow is possible to send since the sent flow will replace everything
