LST during 12/12??? PICS

Hey guys, this is my 2nd grow and im a little pressed for space vertically. I was wondering if i can LST my plants even though they are 2 weeks into 12/12 on 23w CFLs. The bigger one is 6 weeks and showed 2 white pistels 10 days into 12/12. The smaller one is 4.5 weeks old and i think might not be mature enough to show the sex. And also are four 23w CFLs (soft white) goign to be enough lumen output for these two plants? What are those yellow/brown spots? Let me know, thanks.

yes u can lst them now but it wont improve ur yield much like it would if u did it in veg

that's fine i just need to control their height