nothing is going to change at this point.. not all plants grow donks. sometimes it's a function of "too many mouths" per sq ft... too many colas to feed. 2-3 colas per sq ft is what you want. this is just a short bush either by genetics or an environmental cause.
i've got a couple plants that shit the bed in this respect... just some trait similar to the dr. grinspoon genetics... healthy otherwise.. lots of light.. just shitass genetics in those 2 plants.
are these autoflowers? that's going to be a common result, lol.