Not really
I don't know what they could have in mind when you were told that. You do not want a return line from your regulator with a bg400 electric pump mounted in the rear of the car. The only time a return line is advisable on the regulator is when you are using a mechanical belt driven high capacity pump. I recommend mounting the regulator in front of the carb so that the fuel in the line's on the secondary side is forced in the needle and seat under acceleration and not artificially spiking the pressure that the regulator sees when the demand for fuel is at its highest which can cause a drop in fuel level and a bog in some cases. When you are at the finish line your fuel system is flowing at your engines max fuel requirement at that moment. When you slam the throttle closed the demand nearly stops and the fuel tries to continue to flow in the needle and seat's, then a bypass at the regulator would be helpful, possibly until the one on the fuel pump can regulate the sudden demand change. Otherwise, a return line at the regulator with your set up will take from what the pump would have for the engine's sudden demand at launch.
You are all set the way you are Mike, in my opinion
Bruce