Also, even if you go 12-12 from seed, the plant won't start flowering before week 3-4. These ones I'm growing now started in day 27.
The plant you have now is obviously expressing very indica dominant traits. That in conjunction with 12/12 from seed is a big part of why it’s still small. Some plants with less indica take 6+ weeks to mature enough to flower.
I grew a perpetual SOG the last 10 years. I ran many different genetics through the system, and the best yields came from sativa dominant hybrids. Specifically a sativa dominant white widow was one of my best yielders, it took 10-11 weeks but was worth it every time. I ran that plant for 4ish years as clones from one original seed. The sativa is where the nice long spear shaped colas come from, and if you get the right phenotype you can easily flower a 7-8 inch clone and get a 25-30 inch plant that is mostly nice dense cola. Hitting an ounce a plant is doable.
In my experience heavy indica plants don’t stretch enough for the best yields, and tend to want to branch out more then is ideal in a sog grow instead.
Having read through the thread I saw that you don’t want to run from clone or have two grow spaces which can make it tougher to dial in a grow but doesn’t mean you can’t so your thing. If you are just thinking 12/12 from seed in a SOG, I would find a nice hybrid.