Every story world and cast are different, therefore, every Inciting Incident is a different event located at a different point. If it arrives too soon, the audience may be confused. If it arrives too late, the audience may be bored. The instant the audience has a sufficient understanding of character and world to react fully, execute your Inciting Incident. Not a scene earlier, or a scene later. The exact moment is found as much by feeling as by analysis.
