Many of those statements are factually correct in theory only.

The statement regarding the temperature of the underground tanks it true in theory. But, in reality, the ground temperature at the tank depth (4 feet or more) doesn't vary all that much. A 10° difference would be a lot of change throughout the day. It's a negligible change in a gallon of fuel.

The vapors produced at the nozzle when operated in the high speed mode are also negligible as compared to the amount of fuel delivered.

The desire to minimize the air in the tank is also correct. Letting the tank drop below 1/2 allows more air into the tank and permits more fuel evaporation until that air becomes saturated. The question is how much fuel can 20 gallons of air hold? I'm quite sure that the amount is less than four ounces. Therefore the savings can only be two ounces when filling at the 1/2 way point. It now takes twice as long to fill the vehicle. Is the additional ten minutes of time expended to fill at the 1/2 way point worth a savings of $.05 ? Probably not.