It looks ready to me. That was the size I performed the first pinch to make 2 branches. When those two have 4 nodes, pinch each branch again for 4, etc. The 4-way LST tutorial suggests a 3rd topping for 8 future colas, but you can stop at 2 or even 1, depending on your horizontal space.
Later, you'll have to tie down branches that over-grow your canopy. Nature is seldom neat and tidy. ;-)
Yeah, i think it is lol im a newb also...it has been 110 degrees where i live the past week so keeping that exterior closet cool has been tough lol...i dont think its nute burn though..someone told me a potassium def. I gave it some nutrients and it hasnt gotten worse
I just FIM'd a NL X BB and she took off real fast, as a matter of fact I missed the first FIM lol. went back and did it again... Fimming is a lot easier on the plants than topping.