Just experimenting with ghost cams etc, seems as though when the idle dips too low, engine stumbles and causes idle rpm to drop below idle setpoint. Eg, if my desired idle is 850rpm, when pulling up to a stop, the idle dips back down to 500rpm, before correcting itself.
I've tried altering idle airflow to help, but can't seem to get it where it behaves in a drivable fashion, as the more idle airflow I add, the more idle hang I get, which delays the issue, but is not recitfying it