I have had more heated discussions over stair shootoffs than any other set elements in the history of my career.
For some reason, mant people cannot understand that you cannot build a stair on stage without either an L in the staircase or a landing with a backing flat and a ceiling flat.
My experience in filmmaking has taught me that if you give the filmmakers an action toy like a staircase, they WILL use it, and they WILL want to pont the camera up the stairs, and they will see the grid.
A model is a useful tool to explain the shootoff problems that stairs present. I am a big fan of models, however, time does not always permit. The next best thing is a sketchup model, its worth throwing one together if you are having trouble convincing the powers that be.