Fuel Pump Hazard

When getting my new Leon SC FR from the dealership back in march 2015, the technician told me to never exceed the "12 mile range" mark (approx. 20km). Reason being that the fuel pump could start sucking air whilst cornering etc., thus overheating and burning up. Anyhow, I've done it once, driven the car (1.4TSI with cylinder on demand) until the range was still 12mi/20km, for about 38mi/60km after the fuel light went on. Very easy on the gaspedal, that is. I never went that low again, seen as that's totally unnecessary. Official specs show that the "fuel reserve"(= light on?) should be 7ltrs for my car, so it's not hard to calculate when the tank would be empty, using the average mpg or l/100km.