it is absolutely possible to pull a lb with scrog, kept the plants under the screen until roughly 90 percent was covered then let them grow where they wanted, about a two weeks after this I treated with phosoload to keep the canopy tight, level and bring the light in close I used a light rail to slowly move the light a short distance to bring it in closer without over heating.
in my unprofessional opion scrog is the best way to grow with the screen you can grow multiple strains effectivly using the screen to keep them all even and you have complete control of the plants footprint for better lighting distribution, especially if there are height restrictions
the only cons to this system is how labor intensive it can be everday bending the stems under the screen, keeping all the leaves and small buds trimmed away under the screen, and not having the ability to move the setup once it is going. There also tends to be more of a mold problem due to how tightly the buds will form sometimes the screen will hold two or three small colas right next to each other or even intertwined on each other.
on a side note i am getting ready to set up another scrog and instead of using a standard oscilating fan I am going to run 4" pvc drain pipes between the rows of plants with large holes in it and a 4" votex fan to push co2 enriched air up and evenly throuout the scrog, I am hoping this will help
b est regards