Good point, Gary. The solenoid needs to be right next to the pump to have an acceptable run time after closing, and the valve must be able to handle very high suction.
Otherwise, it will be a very long wait as the fuel in the supply hoses is extracted under near vacuum- shrinking the ID of the supply tubing, etc.
I first convinced myself it could work via pinching off the supply hose with pliers 3 inches from the pump, but then found the solenoid valve located there didn't close it hard enough against that wicked suction.