Yeah they can get massive. I wouldnt even want to see what would happen if I didnt top and fim the junk out of them ...along with scrogging them when I first put them out.
I mostly like to start them early due to the harsh environment we have here outdoors tho. We can get really hard late frosts here out of the blue and I've almost lost plants because they were too young when I first started growing. More established plants are more forgiving because you can cut alot back if things go wrong.