When to stop defoliation

Stop immediately, would be my advice. Removing leaves will slow maturation due to the reduction in energy production. Strangely, one fellow says not to do it because you will lose some weight from the buds, then does it himself and advises you to do it too! Why would you do it, knowing it could lower your harvest potential !?! During flowering your plant needs every healthy green leaf it has to be able to make the most energy possible, so that she can grow her biggest and best flowers. Remember - maximum amount of healthy green leaves = maximum energy production = maximum growth = maximum cannabinoids. It is that simple and this is also basic plant biology. Each healthy green leaf removed means less energy produced, means slower/smaller growth. Hope this helps,....... Organoman.

You should do it 2 times, the first one the day you filp to flower and usually i do another one during week 3/4, don’t take out a few leaves a day or your plant wont recover fully every time and you’ll lose some weight on the buds

It depends on strain but, generally after 3 weeks in flower is when the plant will stop producing new fan leaves.