There are two different kinds of screenplays in this world. One is the... screenplay. And the other is the shooting script. The former is what a screenwriter writes, sells and what the actors get. The latter is based on the former and includes technical information such as camera angles, scene numbers, notes about sound, lighting, the scene, etc.
I would like to write both at the same time, but then later export versions with and without the extra information. Is there a way to do it?
Perhaps the easiest way would be to run the raw LyX file through a text utility such as sed or awk which would write lines ending with "//'Director' style" to one file, those ending with "//'Description' style" to a second file, and everything else to both files.
This would give you two "complete" LyX files.
You could use key bindings to map one or more unused keys to the relevant line endings.
HTH, Robert Thorsby