The main advantage is you can motor the engine longer and dual igniters giving better combustion. That brings in more air also lowers the existing EGT giving more margin for EGT to stabilize. Since FADEC is not going to shut it you may allow the EGT to go closer to the limit but I am not sure whether it's wise. FADEC being a computer can simultaniously monitor multiple parameters for a start abort which humans may not be able. In CFM engine in manual start if EGT reaches limit before N2 reaches 50% auto shut down will happen. Dual ignition is also provided in an auto starts after a start abort. Auto start is very smart. When EGT rises rapidly it cuts ignition for 6 seconds and attempts two more starts with 7% less fuel flow on each occasion before aborting the start.