Repeat after me. Light saturation.
If your plants are getting weak/inadequate lighting then they would benefit from 24/0. If they are getting proper light, they will not use 24hrs worth. The rest will be wasted electricity or worse, start to degrade the chlorophyl in the leaves and damage the plant.
The notion that leaves grow in the sun and roots grow in the dark is not true. The plant grows as a whole. The leaves use the energy from photosynthesis along with the nutrients & oxygen from the roots to grow together. When the lights are off, the plant uses its stored energy to grow.
I have done 24/0 and had no problems. I read about light saturation. Then I really considered the actual difference in growth rate rather than what I expected or wanted to see. I see little to no difference using 20/4 or 18/6.
IMO youd be better off dialing in other environmental aspects of the grow. You have much more actual control of growth rate and eventual yield if you focused on things like soil quality, air circulation, light quality, maintaining a healthy root zone & healthy foliage, training, etc.
