[eBirdman]

I expected some latency in the end gauge reading because the "end user" regulator was partially closed... air compressor' regulator was initially set for higher - 50 psi while the "end user" regulator was set to only 20 psi (partially closed valve)..
Nevertheless I did not see any latency... this is what I've learned : pressure regulator, at least as it is made in this example, only regulates maximum pressure limit of the incoming flow, otherwise it is transparent to the incoming pressure allowing the backwards flow release...

[eBirdman]

Too bad there is no way to change the schematic image to the first post in this thread - it is wrong.
I did not find any manual on-line for the 5 port solenoid I chose to use, hence only when I got it and tried I found out it cannot be used in this application.
So I am changing to the one which was recommended by maxspongebob 3 ports 2 position 24V (my controller system uses 24v) .
Final (I hope) diagram is attached.