Flow Forge (im treating this like twitter ) was not around 5 years ago when I needed individual instances for each user. This is not external and has no access to the big bad internet.
If the Original Poster was going to say yes or outline something that needed what I'm up to I was going to recommend https://flowfuse.com/ I've had to recommend it a few times in the last few months. If it was around 5 years ago I would have less grey hair.
01 - I recommend paying for flowfuse.com
02 - or pay someone else to do it for you -----> https://flowfuse.com/
I do not think that a link to flowfuse should become the default answer if people want to learn and join me in the grey hair club