you can keep an auto in veg almost at will by removing any leaf that's splitting into more than 3 points. beyond that there's little that you would actually want to do like mess with the environment so that the plant stays in veg (cold works!) or less light like 4-6 hours.... autos are autos, try these new gens : fast flowering photoperiods. I did a full cycle in 12 weeks and was very impressed ! for you you could keep those in veg for as long as you want then flip to flower and perhaps be done in 4-6 weeks (which is short !)