Just a few observations to note.
1. The three plants in 2 gallon plastic containers are bigger than the 2 gallon Smart Bag plants. I do think the tap root vertical growth is important; maybe, more so, in coco. The plastic pots are tall and the tap root has more freedom to grow and then root out. On the other hand, the dirt bags/smart bags are broad and tap root is restricted by about 1/3 or more of vertical growth. That is probably why the outdoor plants can be monsters--tap root is free to grow.
2. At four weeks I watered to run-off. Looks like it takes a little bit shy of 2 quarts to get a good run-off. I did not water to run off, until now, at four weeks. Keep coco lightly watered while young trying not to encourage stunting and to keep the roots searching. Looks good so far. Not completely blemish free, but, good overall health.