A 12/12 grow from seed does not give you a mature plant in the way a six week veg gives you a mature plant. Even in a twelve twelve from seed grow the first week or so is vegetative growth until the plant realizes it's time to bloom because of the light schedule...but the plant is not naturally mature and ready to be flowered. As for auto flowers, they don't necessarily make auto flowering strains. An auto flower strain flowers regardless of the light schedule. They are ruderalis strains and will flower when they get ready, they are not tied to a 12/12 light schedule to flower. Personally we can do almost anything with cannabis and anyone can stick a seed in the ground and get bud from a 12/12, however, why just stick seeds in the ground and do a 12/12 when you can take the time to allow the plant to mature naturally and get a much better harvest? Also, I've done a couple of 12/12 from seed grows and the plants have never reached maturity enough to start alternate branching. Some of the girls I veg for six weeks don't start alternate branching until after flowering begins.
in a 12/12 from seed grow there is no change in the light cycle to cause any realization that its time to bloom. the only point in time a weed plant can flower either male or female is once its reached sexual maturity. i quote the cannabis grow bible, "...the plant must be mature enough to present its sex. An immature plant will not show sex because initial calyx development is not photoperiod-related." "...sex is not genetically determined until the third week of growth." you do have a point on the autoflowers as i dont have any experience or info on that. alternading nodes on branching is well known way to tell sex but i understand completely that some strains and seeds may not do it until after showing pre flowers or being put in flower.
Country- sounds like you can combine both your clone and veg area to save space and time of a dividing wall for a seperate room. i like the idea of the home-made SCROG on wheels, cant wait to see how that plays out.
1BMM- good looking buds! nice amount of different strains as well!