&cleanishflag will show the director direct overlay messages, while hiding most others things
&dc) , which will cause chat messages to go to ONLY the director.
&covercan be used to have a video be zoomed in and cropped, so it fills its window area completely. Useful if you don't want any gaps between videos.
&fadein=500is a new parameter; also available as a director's room toggle. Has videos fade in smoothly; 500 = 500ms fade in time.
&tipswill show a help-screen on the guest joining (via @jcalado)
&limittotalbitrate, which tries to limit the total outbound bitrate to some max total value, via the publisher's side. This could be useful if you are broadcasting video as a director to the room, but only have a fixed amount of upload bandwidth or CPU. This bitrate limit does not include data used by audio, webp, or meshcast in its calculation. It is loosely accurate, but no promises. It is applied to scenes and solo viewers as well - not just guests. Example use: