Specify Dedicated Server command line running in Editor

How do I specify a custom command line parameter for the dedicated server in the Editor? The “Server Game Options” passes in URL arguments and the tooltip says to “… Use the Command Line Arguments field below”. Well there is not one.

121327-gameserveroption.png

I confirmed in my server build that I am getting the passed in command line parameters, but it would be nice to be able to do this in the editor too.

Uncheck “Use Single Process” and the field will show and it even works!

See link for all the options:

I don’t get a dedicated server instance and I am unable to have multiple clients running. So this is even worse for me than my workaround.