A friend of mine kept one in veg for 8 or 9 months. This thing was a monster. Had its own little eco system hehe. He didnt even clone it though, makes me wonder whether it would even be worth having a plant in veg that long unless you wanted cuttings.
Theres some theories to suggest that genetic vigour is lost when successive clones are used rather than a set mother, I suppose theres just more opportunities for change in that system.
Its not of massive importance to a casual grower, but then its easy to keep a litltle bonsai mum in veg somewhere aqs cheaply as possible and invest all your growing energy into where things start to flowe r