They are each planted in 1 gallon smart pots and w...

Those air pot, grow pot fabric pots are so cool and really seem to do amazing things. I agree with the others on timing of transplants. I've seen a grower who used the smart pots and rather than germinate, they simple settled their soil and popped the seed in, it was the largest of the 3 plants(other 2 paper toweled). I think this grow may just need as much healthy strong light as possible and a moderate level of nutrients and hopefully they will bulk up before harvest. I guess that's the beauty and curse of this place....learning. Bleh why can't it all just go perfect from day 1. Happy growing to you congrats on acquiring some good supplies for your current and future grows.

Autos are very delicate and any kind of stress will affected them severely. Smart pots are meant to be used as a final container, specially in autos, because the roots, as you saw, get tangled in the fabric and when taking it off, you can hear the roots tearing. An early transplant is ok, before the flowering phase, but not out of a fabric pot. Early topping or FIM ( between the 4th and 6th node, helped developing more bud sites.

In my opinion, I believe the height was affected by the transplant and small container size (1gal). These autos are on a short time schedule, so planting an auto in its last container will let the roots grow uninterrupted. That's just one factor. Lighting, proper air exchange and feedings will also affect the height. And lastly genetics. For the most part, soil grown autos stay pretty short anyways.