Looks like you may have answered my question I posed earlier (was it in this thread? I think so...) Anyway, I was wanting to know what was best for conserving juice insofar as one can when one is a chain vaper. No one seemed to have a clear answer (I even Googled it!) but the theory seemed to be that the smaller AFC opening the more "siphoning" of the juice, thus more of it burning on a draw. Seemed logical to me...and you seem to be confirming it! Interesting! I was beginning to suspect as much from my fumbling attempts at "testing" I've been doing the past couple of days.
The thing that confused me a bit was seeing a post by someone saying that the open air flow thing was for "cloud chasers" at hight wattage who didn't care about wasting juice (or something to that effect). Got me scratching my head, wondering.
Yes the cloud chasing wide open airflow does appear to contradict my observations. However I don't think cloud chasers open up the airflow to get more juice to the coil, clouds being achieved via huge wicks - max vg - high wattage, instead in this scenario the open airflow is likely all about cooling the vape.
That's just a theory though...I am no expert!