Thats the nice thing on photoperiods, you can do as you like it. I switch to 12/12 if iam ok with the shape with my Plant. That means if iam ready with topping and supercropping, when she is well prepared for flowering. if you dont want to do any training, you can flip anytime. some Big growing companies go with 3 branches and let them 4 weeks in vegetation. What are your plans=? LST/ Topping=? -Thats the nice thing you can try very much things, and you just can let her grow until you are statisfied with the Pants shape