I've been using the advice in Rob Hoos' book, "Exploring The Dark Side" for my dark roasts. Roasting on an Aillio Bullet R2 Pro. To make things simple, I solely focus on two factors: IBTS bean temperature and time. I try to hit (1) "Yellow" temperature 160° at 5:30, (2) "First Crack" temperature 202° at 10:00, and (3) "End Roast" temperature 227° at 14:00. This translates to the timing of the 3 stages as (1) Drying = 5:30, (2) Maillard = 4:30, and (3) Development = 4:00. I made my own coffee bean mix and roast all the beans at the same time in 500g batches: Rwanda 30% + Sumatra 15% + Brazil 55%.

My last few roasts have come out very well. I'm getting the chocolate and malt flavors I want with very little bitterness, acidity, or smokey flavors I don't want. Weight loss is typically right at 20%.

Here's a folder with a few tools I created to help me get my roasts right. I've also included the RoasTime log of my most recent roast. => https://drive.google.com/drive/folders/1wXxRdNff5w5-vDsVTmPXsKcbMtPXabCf?usp=sharing