Ye, I think the best way to deal with the 11 to 13, if that route is taken is to take that troublesome wedge between the gray and black lines out of play by making sure to come off the long rail with the CB. This way, if a bit low, playing to the corner rather than the bottom side pocket saves us a bit.
In general, I think going to the second rail just gives us more room for error and still be fine whereas the way it is diagrammed, going one rail to the top side pocket demands a very precise line off the short rail and really good speed control with the 3ball looming. Under pressure, speed control fails first so the two rail option for bottom side or corner just seems like the safer and higher percentage approach as long as you are comfortable playing some inside english if need be.