I’m looking for someone to answer you question.
It would most likely be better to create a script that launches a server and a clients in game. Make sure to run with -game -messaging -sessionID=‘GUID Number’. Make sure to use the same GUID number for each session you are opening.
You can visit here to create a session id without any hyphens: http://www.guidgenerator.com/online-guid-generator.aspx
The SessionID allows the UFE to view all of the running games as one session. This allows you to parallel test across multiple machines. This even allows you to send console commands to all of the machines at once. For example you could have the clients join the server. You can tell the server to change maps. Or you can just tell the group to split up the available tests and run them.