To run the NR Runtime for a specific "Project" and to further work on another project with the NR Editor, I found Steves instruction at Installing and Starting Node-Red - Steves Node-Red Guide with
node-red -p 1881 -u user1
Further down his page and with the comments there is also how to separate the work with using different users.
My problem is this: being on an RPI and started the standard user "pi", I can't find the "flows.json" or project files .. only some old files which don't have the content I'm seeing with starting node-red with <ip>:1880
and <ip>:1880/ui
and there is only .settings.json with todays time stamp.
Any idea how to find the "current" project for using it on port 1880 and have a working node-red setup for developing a different project/user at e.g. port 188x ?
Solved:
I had overlooked that a previously loaded Flow was loaded within a Project. I deleted the flow within the project, but left the project. Thus my new flows were led there.
Now that I know where my new flows are located, I can do the multi session/port setup.
Thanks for the attention