Overall overlap, or lobe center understanding?? ¿.

from my very limited understanding large overlap is ok for high RPM because there will be enough airspeed to cram fuel/air into the cylinder from the intake without the cylinder feeling the need to steal its neighbour's exhaust. I recently chose a cam for my low-ish comp propane 318, and overlap was something that i definitely considered because the propane converter relies on a vacuum signal to draw the fuel through. no vacuum = undercarbed at low RPM.