I definitely need to get a second thermometer to monitor the MET! I have been "burning" my beans. So far have 10 roasts under my belt from three different roast sessions. This last session I thought that everything was going well, was able to end the roasts right at the very start of second crack. However, both of my roasts have a definite burnt/charred taste that lingers. My next roasts I will try to not hold the max temp max fan as long. For now I am sticking with the same type of bean, just to try and get some consistency going.
I have been trying to follow Jim S's guide on roasting.