My friend I would start flowering right now. The plant is plenty big for bud bearing. TALL IS NOT BETTER IN AERO GROWING. With a tall plant you may get more buds but you will get smaller buds and the lower buds on a tall plant would have the medicinal value of an aspirin. Ideal plant height is 22 inches. These plants produce nice fat juicy buds. Keep in mind that using accelerated grow methods is not the same as trying to replicate nature indoors. The short plants produce buds. If I was in the leaf growing business I would grow tall plants. I WANT BUD.
All the best to you.