Activates the Preview layout for the director's room by default
There is a new button in the director's room. It lets you toggle between a Preview layout and the normal Director layout; the Preview layout will mirror what a basic
&scene=0link would look like.
Useful if you want to switch to a guest-like mode as a director, and then switch back as needed to the director's room to make adjustments. To enter this mode by default,
&previewmodecan be used by the director.