Defoliation

Too much IMO. Although, I've seen other growers strip off about the same amount before and it's been fine but it seems to take awhile to grow back. You certainty want leaves on the plant when in flowering. Leaves are like "solar panels" for the plant. They absorb light and transfer that energy down the plant for growth. Here's a video I recently released showing Before & After defoliation:

Also, here's a video from awhile ago which goes into a little more detail "How To" defoliate for beginners: https://www.theweedtube.com/video/how-to-defoliate-cannabis-plants-beginner-s-guide-to-defoliation--30936

In general, leaves are the "solar panels" of plants (although there are some leafless plants such as most cacti). Most plants have the ability to lose all their leaves and re-grow a new set. Since ancient times, bonsai artists have determined that pulling all the leaves off a plant twice will result in the third set of leaves growing back smaller (and in some cases more numerous); this is exactly what you are hoping to achieve by defoliating the plants twice in early flower. I do it on day 1 and roughly day 21 and get massive yields. It doesn't seem like it would increase flower yields, but it does! Good luck!