...can be used during flowering, yes, but I found that you have to be extra-careful during flowering (particularly after watering when the plants are soft)...

...because I DAMN NEAR BROKE A MAIN STALK OFF while moving it back into place after some LST training!

I caught it quickly, after only a little bit had peeled open (this was arguably the /other/ main stalk on the plant, and therefore /important), and wired it back together with picture wire.

No bad seems to have come of this, thankfully, but BE CAREFUL. At any stage. When doing SCRoG/LST, always (always ALWAYS) bend the plant manually carefully into the shape or position you want it, then tie it into position.

Do NOT use the string or tie or whatever to 'pull' the plant into position. Bend it into shape by hand.

There's me rant fer the day