No. don't defoliate. Only remove yellow leaves, for by the time they are yellow, they have served their purpose.
Defoliating during flowering or at any time really, reduces your plants capacity to produce energy, thereby slowing growth and/or maturation.
The old leaves are also a source of carbs, sugars, amino acids etc that your plant will draw upon during flowering as it is more efficient to recycle these "stored in the older leaves" elements as it is to grow flowers AND make these elements from new during the energy intensive activity that flowering is.
This "recycling" is also why the older leaves go yellow ("the fade") during flowering, even on otherwise healthy and well fed plants.
So, removing leaves not only slows growth due to a reduction in energy production, it also denies the plant of a ready source of vital elements it needs for proper flower growth.
"Lollipopping" your plants at the end of veg/beginning of flowering is the last time you should ever remove any foliage, unless it is yellow.
"Bud sites" being shaded is ok, the energy your plant makes gets used throughout the entire plant, wherever there is growth happening, so the lower and smaller buds will grow just the same as they are now, with or without the leaves, so there really isn't any point to removing the leaves at all. Best left in place to make the energy needed for maturation, as removing them will slow maturation, due to the reduction in available energy.
Hope this helps,..........
Organoman.