I've cut the stalks to the level I wanted them to reach when the stretch was over and I felt they were too close to the light with no more room. The buds were still small. The canopy was too thick to bend them over LST. The new top will be pair of colas instead of the single spear. I don't know if that was the best way to handle it, but it worked and I harvested a lot of bud in the end.