you dont "have" to top it twice to get 4 main colas. i top mine once and get 4 main colas.. Also DontTaxMeBrohad good advice.. btw, you should clone those cuttings! currently i have 2 mothers but when i use to not have mothers id top for 4 colas, use the top as a clone and just kept the cycle repeating.
Looking good. Uncle Ben's topping technique was at the white line but really you can top anywhere and still could produce 4 main colas's with some training. I tend to top at the 5th node and do some super cropping and still make a few cola's per plant. The reason I do this is because I like the space between the soil and the cola branches for watering.
You need to add more Nitrogen. The yellowing and purple petiole shows N def.