It will stress the plant a little. It's said that you should be done LSTing two weeks before flowering. I did just a little LST (maybe 30-45 degree bends, not 90 like in your last pic) at three weeks into flowering, and noticed it just stopped growing for a couple days. But, everything was fine in the end. I'd just let her go, maybe get some supplemental cfl's if you're worried about light penetration. If it's a height issue, then do what you gotta do... Just my :twocents: