High bro,
This would be the perfect time to do your first defoliation.
There are 2 reasons why someone would use defoliation on cannabis plants.
1. To create airflow between the leaves and buds.
2. To cut away small buds at the bottom that will never develop enough to be taken serious. While they use energy that should have gone to those fatties at the top. And you want to get rid of the leaves at the bottom that don't get enough light to be useful.
Now would be a good time to use your first defoliation for creating airflow.
And you want to do your second defoliation around 2 weeks after switching to 12/12 because by then you can see which buds don't get enough light to develop into a fatty.
When you follow these steps you make sure that your plant is focussing fully on the big, fat and juicy buds at the top!
Happy Growing! 😋