@barrkel: Hi Barry. Thanks for sharing your thoughts.
Unfortunately for us, the gas water heater was installed in the garage by the builder when the house was built. In the winter months, it really gets cold there and the temperature differential between the hot water and the ambient temperature of the garage leads to waste. After installing this hack, I also wrapped the gas water heater in insulation to help reduce the loss. The perceived constraint of having to stick to a strict schedule is actually not that bad since the water still remains warm for quite some time after the heat is lowered.
@Jeff Birt: the servo can only physically go from 0 to 180 degrees: the way the mechanical coupling works with the valve, calibrated to be on the HOT setting at the full extent of the servo's arm, it is impossible to get into a dangerous situation where the water would become too hot. The water never gets stone cold as the temperature is only lowered to a low heat setting, so it never takes a huge amount of energy to heat it back up.
I plan on having a follow-up article on the actual savings in a few months: the proof will be in the pudding