I'm curious about my experience with divots. Normally I use a basket on my Weber gas grill. I use this on a rotisserie with a high speed motor ( about 60 rpm). Typically, I roast 1 pound batches and I get 1st crack between 8 and 12 minutes and finish the roast early in 2nd crack around 15 to 17 minutes. Sometimes, as with Sweet Maria's French roast blend, I'll go into 2nd crack pretty far. I am generally pleased with my roasts flavor - usually using them for espresso. However, I almost always have some divots. This offends my sensibilities. I do not believe it affects the taste of my coffees - whether lighter or darker roasts, I don't really detect ashiness or burnt flavors. I have tried slowing down the early stages of the roast and I have tried turning the heat way down at 1st crack - still I always get some divots. But here's the thing I'm wondering about. I turned my wife's copper lamp - that was originally a kettle - back into a kettle and rigged it to turn on my Weber charcoal kettle rotisserie. I put some copper strips inside at 90 degree angles to stir the pot, as it were, and I roast 1 pound batches in it - with a slow motor (about 3 - 5 rpm). I get 1st crack around 10 minutes and finish the roast at 15 about 1 minute into 2nd crack. And, I get no divots! Why do you suppose this happens? The heat level is about the same. My limited theory is that it must have something to do with air flow. The basket in the gas grill is made of aluminum and has lots of holes in it. The copper kettle - well, it's copper and as it was originally a kettle - it only has the few holes I drilled in it to give it some air flow.
What do you think? If it didn't get so darned hot and wasn't so hard to handle, I'd use it all the time as it really yields a very pretty roast.

Whenever I've had a few divots my temp. around 2nd crack has been flirting on the high side. Usually with softer or decaf beans. I've never done tests to see if too high a charge temp. and rapid surface heating at the very start of the roast accentuates these happening later in the roast.