to answer your questions...
The final version of the ffm series was 17 racks per hour which comes to approx 3.5 minutes per cycyle. Now nobady was that fast as to be able to load and unload it but if you had the racks of dishes ready to go,you might be able to come close to that.
On my friend's machine, the one switch interrupts the timer motor so you can make the cycle as long as you want once it fills to wash. The other selects either 180 degree booster heater water from the 6 gallon booster or water direct from the house supply.
The cycle consisted of a full fill and wash, a drain, a short fill and purge, a drain and then a full rinse and that water got saved for the next wash. Machines with sump heaters would keep the water hot for the next wash.If they lacked the heaters, then the water could cool off.
The high temp "H" machines had the 6 gallon booster on the right side of the frame under the tank which supplied the 180 degree final rinse.
Larger machines dont usually have a heated tank for the rinse so much as they depend on an separate final rinse booster powered by gas, electric or steam .
Did I get to them all?