It does still have a focal length because it creates a vray camera. But it tries to "fake" a flat ie front,left,right viewport. You can create a rig and then rotate it to be a plan. Alternatively, create a vray camera with a really small lens but move it away a big distance to flatten out the perspective. That's effectively what that script does. The rig is much handier though.
Unfortunately, it the only way as you cant render a front "elevation" in the front viewport if your setup rendering with Vray sun and exposure. It does give good rsults doing it this way though.