Quick Generate does the job of Batch Generation from the UI.
Command Line Generation generates a specific project.as it did in Classic, to the best of my knowledge. Not something I used but there is a page on my site about it written by Bill Albing and that seems to refer to a command line for each project.
See www.grainge.org for free RoboHelp and Authoring information.

@petergrainge
Use the menu (bottom right) to mark the Best Answer or Highlight particularly useful replies. Found the answer elsewhere? Share it here.