never on flower stage. i may not know a lot on LST but i am learning as well so anyone's input is great, especially if im doing it wrong. how far is your light and what kind of light led sodium clf etc.. i am using a t5 and im about 36 inches away from the plants (i found where i can keep temp and humidity in a good zone and its at 36 inches) basically seeing yours are staying small and bushy id wait and maybe move your lights up a few inches to cause the plants to slightly strech and be able to bend the stems to preform LST. from what the article states you need to top the plant and then bend it to cause the lower nodes to grow as a branch causing new nodes. if this is incorrect anyone please correct me. I however didn't top my plants and i had two standing over 16 inches which every plant has grown a full canopy, with a few new nodes each.
basically look how a Christmas tree forms they fill in on the bottoms by growing out well the can plants grow up to the light so lower branches cant make it up and out to the light due to the top being so full. so was most growers do is top the top part of the plant and cause the plant to stop vertical growth and grow new nodes that will take over the vertical growth. this leads to more yield per plant.