Well, the mill city guys do talk about something called aroma stripping caused by too much airflow in drum roasting. I think I may have run into it myself with too much air at the end - for a while I was trying longer Andino type fan profiles, and I suspect that high air right at the end where the beans are most vulnerable is especially risky for “aroma stripping” if indeed that’s even a thing.
Yea I agree that you’ll probably get unevenness if you’re relying on low-air heat buildup in any serious way. Unlike most of my popcorn popper roasting, the ikawa doesn’t require buildup to get up to crack with sufficient momentum. I used to hand-stir like a beast to prevent facing and such. Don’t miss that!
I would love to hear from ikawa about fan speed as well. The reasoning behind the fan speed choices as described on their various coffee bags seems…diverse. I’m especially curious about the Andino air profile. I’ll start a new topic on it too.