Unless you are not paying attention to the best growers on earth, everyone is defoliating, it is standard practice in most grows, and yeah it has tons of benefits, such as removing useless leaves causing shading that will impact bud yield, and also pushing the plant to have generative growth.
It also helps with pest prevention.
When to do is is more of the question.. But you follow the guys who have been doing it best they recommend the anywhere as early as the week before, when you flip, to within to 1-3 weeks into flowering.
you forgot the link to a side by side which proves that defol gives a bigger yield !