Dude, I'm with you on this! My high ass was thinking this same shit but was afraid to make the post. lol Thanks and +rep just for asking. lol But I think you could attempt this by using a cfl's around and above the pot ata wide diameter. this method would cause the plants to stretch like fcuk and the stems would fall beside the pot as they began to not hold their weight. Or you could tie em down that way. Then as you reached your desired lenth switch to 12/12 with the lights at smaller diameter under the pot. Just a theory while high!
But what do I know, I'm only on my first grow. lol