I recently attended a panel during which we discussed actor preparation. An actor mentioned that he didn’t see the need for all of the prep work as he just booked a project that he did not do anything for, just went in and “threw” the audition on tape. BAM! He was hired!
It may have been luck. Or likely, they needed the specific look, and he matched it.
You are not doing the work simply to book the 2 line Coroner role. You are doing the work to establish the technique you will rely on when you are reading for the series regular and are asked to fly to LA to be tested for a role.