oh you will be surprised. when flipped to flower they will shoot up for 3 or 4 weeks, as long as the light is high enough and the rest of the environment is good. could just be that the genetics tend towards shorter plants, as youre growing inside that should be a helpful/good thing! i wouldnt worry about trying to get more stretch. do what the PLANTS are telling you...and if your leaves are lime green or yellowing they need some food. or theyre overwatered but probably hungry. whats ur water/feed schedule like?