I did this once when I realized I never picked back a sativa strain that I was growing during veg. It was branching out anyway, so I forgot. In order to keep it from getting too tall, I pinched it back in flower. At the site where I pinched it, the bud sites grew tremendously, and the plant looked like it had a giant lollipop in it.
Yield was normal and the potency was as expected. The only difference was that the plant was kind of ugly looking, compared to its more symmetrical neighbors.