With the correct nesting / CAM software this process only takes a couple of seconds. Chain cutting is fairly common in industrial applications...and it is pretty much automated with software like MTC ProNest, which also provides for a lot of other time and cost saving advantages such as collision avoidance, best plate utilization and others...depending on the other equipment (Plasma, height control, cnc) installed on the machine.
I have seen some cutting jobs with one start and over 4 hours of continuous cutting on 5/8" and 3/4" steel plate.
Jim Colt Hypertherm