Is is possible to run multiple Node.js servers on the same PC; each running a separate Node-Red flow?
Yes. But each must use a different PORT. 1880 is the default but you can only use that once. So you can use another port for each additional instance.
If you don't want/like the ports, you can run a reverse proxy to push a specific port to a sub-path on, lets say, the default port 443.
It is easy to run multiple node-red instances.
node-red -u /path/to/directory/containing/flows/file -p portnumber
If you specify the port in settings.js then you don't need the
Thanks Totallyinformation & Colin for the good information,