@eeeee Sure. When NodeBB tries to load the values in config.json, it checks nconf value config first. You can send in config as an environment variable to point to the path of a different config file.
e.g. config=configA.json ./nodebb start
So you can have multiple configs in the same folder, and launch separate processes off of the same file structure.
If I run config=what.json ./nodebb dev on my local machine, it will launch the web installer, since what.json does not exist.