yep your right, old thread and 12/12 from seed often show sex at week 3-4
all mine did, all between 1 and 2 foot high in 6L pots 12/12 from seed all show sex after 4 weeks fist white hairs came around week 3 now at week 6 or so I have white hairs all over and buds starting to swell I guess Im half way so another 6 weeks or so to harvest
from the research I have done it seems most finish 12/12 from seed in 11-12 weeks so faster then if you Veg at the cost of yield
but do as I and plant a few more and get the same yield in short time at the cost of a few seeds/clones, my 600W still covers a 4x4 area no matter if it is one hugh plant with 12 weeks Veg or 6 with little veg time, or 9-12 plants 12/12 from seed ..