his problem is the main stalk is getting to tall. not the side stems guys. the side stems are the easy problem. the main stalk i believe his his main concern. Topping it and fimming it wont stop it from growing any taller it will just split the top node and create 2 tops. but they will still keep going up and up. it might still be a option maybe those u can lst. but still might not do what your looking for.. how much more space do you have to work with height wise? how tall was the plant before u put it into flowering? j/w i have about 5 feet in my cabinet and my plants are about 20 inchs atm. with about 10inchs of soil under it
I know the side branches are not your problem. I was just mentioning tying them down to promote other growth below.
Chopping your plant's head off, especially this late in the game, will not benefit you at all, in fact, it can lead to a possible hermi.
You can't bend the main stalk now because its gotten so woody over time but the top of the main stalk may still be easier to bend. You could just tie a slip knot towards the top right underneath a node and gently pull the top down and to the side then tape the other side of the slip knot string in place on the wall or something. Be innovative, people do shit like this a lot just to keep the main cola from snapping their stalks. This will be preparation for that as well as LST.