BdKoss, on your A320s, do you have one or more the packs running during start?
Getting a good airflow through the engines (all rotors turning in the right directions) may help reduce fuel fumes in the cabin.
As engineers, we mostly use manual starts unless there is something specifically wrong with the Autostart System. We have more control over the start: The process is slower, giving us time to monitor specific parameters at specific times. We get to choose when the fuel/ignition goes on. If fuel has pooled in the combustion chamber, a relatively long dry spin ensures that all the excess fuel is blasted out the back before ignition is turned on. EECs are not that smart.