12/12 from seed is possible, but also a waste of time. Wait until your plant matures and shows preflowers, it should go into flowering mode very quickly, if you do it before then its gonna stall out while it finishes vegging and forces itself to mature, wasting alot of time.
than a mature plant, yes. in the end it takes about the same amount of time for a plant to naturally mature or force mature from seed, approx 3-5 weeks, the forced to mature plant will be alot smaller however.