When you grow a sativa from seed on 12/12 from start for example, it won't actually work on the transition to flower stage while it's still seedling and maturing (and will actually progress slower through those initial phases).
i was thinking this myself i have not done any 12/12 from seed runs i am not sure if this would have any advantage
(making them flower earlier) and as you say might even make it slower lol
watching the seedlings grow it is at 9 days and 12 days that i mostly notice the transition to the veg stage
i do not think if the seedling stage was on 12/12 it would make the plant flower any quicker
most of the 12/12 grows i have looked at folk are saying its around 30 days that plants show sex
some claim earlier 21 days but for most its around 30
i am pretty happy with the size the mothers milk plants have stretched to
they have some sativa in their genetics the leaves are getting thinner now
but the frame of the plants is typical kush/indica dominated
with 16 days of light before flower they are at a size where they can make 4 oz or more
if the genetics permits it and they grow some nice colas rather than sporadic nuggets
they are just over 2ft but have plenty of fat branches they are still stretching
with the recent grows i have done i can see that the type of plants i want to grow
and with the plant numbers i am comfortable running giving them some veg time
has the advantage of producing plants with more colas
every time i try to do a smaller sog type grow i am always trying to cut the plant number back
i guess this is the wrong way to approach it, sog is just not for me lol
i cant get my head around growing 9 plants in the same space as 2
i do not want to veg for anymore than 2 weeks
this is plenty to produce plants that will yield several oz
but it will still be dependent on the plants having a big growth spurt during flower
if i was growing commercially though i think i would do it 12/12 with no veg from clone
the yield is there the speed is there, just the consistency of colas is the problem
having the yield in colas is more pleasing to me and easier to chop
the overall quality of the smaller plants is only slightly reduced
also i am happy to report i have got over the superstition/habit of
adding phosphoric acid to the res
i can now say this system is 100% ph regulation/measurement free
peace