Vapor lock- additive?

I solve the shutoff/hot soak/fuel boil/won't restart issue with a pretty basic solution. To shut the car off, I first turn the fuel pump off and let the engine empty the carb until it stalls (maybe 30 seconds or so). With no fuel in the bowls, you get no vapor/boiling during the hot soak and thus no vapor lock or rich restart disasters. When it's time to start, flip the fuel pump on to refill the bowls in about 3-4 seconds then hit the key and the car(s) fire right off. Simple, old school hack!