Fan Control for RoastTime 2.0

I would like to be able to control the bullet exhaust fan while in preheat mode. With the original software I could turn the fan on and control the speed to modulate the preheat temp. I am getting more inconsistent roasts now because of the inability to do this. I have seen large temperature swings in the bean temp probe while on preheat mode doing back to back roasts. everywhere from 185 to 215 all while the drum temp remains the same.