2nd grow with MissUSA

Everything is going great, I also think my plants have stopped stretching/growing, although really close to the lights. I am not seeing lightburn, is this is something should be concerned about? The leaf temp is about 75 degree under the light. Also just sticking with AN Bloom, Big Bud, Bud Candy. Should I be using B52? Also is overdrive worth it? it seems expensive for two weeks worth of work? One more question? Is superThrive bad in flowering? I read somewhere it could make bad things happen in flower because of the hormones it has. thus my question about B52.