@soonerschwab, I'm doing an auto strain next run and I want to top, but I'm pretty hesitant. I'm new to growing, but I think topping an autoflower is something you do during veg, not during flower.
I think I'm going to grow my autoflower strain once without topping and keep a journal on when it starts flowering. Then repeat the same growing conditions with the same strain and top during veg, hopefully leaving a week or so for recovery time before going into flower.