In my opinion, do not defoliate your beautiful plants.
They are relying on every leaf they have to make the energy they need for flower production. Every/any healthy green leaf you remove will just reduce the amount of energy your plant is able to make, leading to slower and/or smaller growth. The older leaves are also a reserve storage of vital growth elements, such as carbs, sugars, amino acids etc that your plant will draw upon for use during flowering, as it is far more efficient to re-use these vital growth elements than it is to grow flowers AND make these vital growth elements, from new, during flowering. This is also why the older leaves will go yellow on otherwise healthy and well fed plants during flowering. These 2 very important facts, are something defoliation advocates fail to understand fully.
So, not only does defoliation reduce your plants capacity to produce energy, it also robs her of an important "stash" of vital growth elements that she has so cleverly stored in her older leaves for use during flowering.
In 35+ years of growing cannabis, I am yet to see a plant that gets rid of its own healthy green leaves for no apparent reason or benefit. Your plants will grow their biggest and best flowers if left alone and not defoliated.
Remember - maximum amount of healthy green leaves = maximum energy production = maximum growth and maximum health.
It is as simple as that and plant biology 101.
Hope this helps,...... Organoman.