It creates a profile for each "user". The first user is "Default", the next is "Profile 1" and so on.
It stores the profiles in the Home directory. Under linux this is
It will start with the Default profile unless you give it something else. Do the following to open it with "Profile 1":
chromium --profile-directory="Profile 1"
You can add a text file (e.g., urls_treas.txt) containing the desired URLs to be opened on start:
chromium --profile-directory="Profile 1" --new-window $(cat /data/develop/bin/comms/urls_treas.txt) &