Well you're right.....extreme changes in temperature WILL give you a shorter plant.
It will dcrease the amount of bud that that plant produces.......SO.....you'll get more bud off a plant you're flowered from a small clone and used recommended temps (night and day), than flowering a larger plant but using 'DIF' to keep it to the same height as the former plant.
Extreme changes in temperature aren't very good for plant material. As the temperature increases/decreases, the plant matter expands/shrinks which causes the plant stress....and decreases yeild.