Nice schematic but on a side note, " is inches, not feet. A simple mistake, but the labels at the top right of your drawing dictate in inches, not feet.

As far as seedling SOG, I'm just not a fan. As long as you have room for a separate vegetative area, it is easier by far to keep a mother plant and grow clones into SOG. With clones, you know the sex of the plants, how fast and vigorously they grow, etc.