Whether or not you remove some fan leaves is not going to determine the final size of your autoflower. If you want big autos there are far more important factors that should be mastered before worrying about defoliation.
Using a good quality soil or medium, in large enough containers, preferably at least 5 gal fabric pots.
Good feeding/watering techniques, proper lighting, good airflow and environmental conditions.
If these things are all in order, you’ll get big productive autos, whether you do heavy defoliation, light defoliation, or no defoliation at all. I hope this helps clear things up for you a bit.
This is a link to my current journal. They’re autos that will be done in another week and change, but you can see my methods from start to finish.
I’ll also be starting a new journal later today for my next batch of autos, I’ll try to remember to come back here and post a link for you.