Is there message multiplexer in Node-RED?
Like a signal multiplexer in electronics: one type of messages can control flow of all other types of messages.
Control message has topic 'control'.
2 other message types have topics 'fruits' and 'vegetables'.
Once 'control' gets payload 'strict' the fruits go to output 1 and vegetables go to output 2.
Once 'control' gets payload 'relax' all other messages go to output 3 (or 1 doesn't matter for the example).
I found router:
It doesn't control the flow dynamically.