I perfer to do most of my topping, supercropping and bending straight from the start. Supercropping however would be a good techniche because if you supercrop the top then the sides will try to catch up and you could end up with a couple of colas.
As far as starting them to flower it all depends on you. If pre-flowers are showing then you are good to go. By looking at your tent it looks like you may not have all the room in the world, so flowering now might be a good idea. However, I wouldn't expect much from each plant, maybe an ounce or two if done right from each. If you veg for another little bit then your yield would increase. Hope this helps, happy farming.
hay dude what happend to the LA CON? I was given a freebir fem seed of LA con and it hermied on me as soon as it started to flower