My favorite chili oils take the chilis just beyond a perfect maillard "sear" and venture very slightly into burnt territory. Many peppers have a natural bitterness when dried, and that slight bitterness added from the barely burned flavor brings out some extra, magical, umami depth. Adding some acidic elements makes for some incredible dishes.

I have found that smoked chilis lose their smokiness with high heat though. I wonder if doing a lower heat extraction might retain those smoky flavors. Sounds like the multiple extraction/blend the author talked about would be worth a shot to get both.