Yes, its too late. LST needs to start at week 2 and continue through pre flower. You are trying to make the plant create more auxins, to promote more budsites and have the side branches keep up with the main cola.
Bigger pots and bigger lights will do that, along with big genetics! If you guys want a thread specifically for LST and tying down for better light penetration, I can set it up and one of you can do a tutorial. Interested, pm me and I will create the sticky and post it in the new growers forum so people will see it and get better use of it there. Just shoot me a PM if anyone wants to take it on. I myself dont do LST, simple sea of green in my tent.