That's the plan here essentially, top everything and SOG it to determine sex and phenos and keep the good moms.I top them, stick the top into a glass of water and put it into 12/12. Or, if I'll be vegging them long enough, I'll stick them in a glass of water till they root, plant them, let them grow a week or two, then flip.
I did put a plant under 12/12 from seed till it showed sex and then revegged it, but that stalled it out for a while and it never fully recovered. It still grew, but it wasn't at it's full potential.