Are you going for just numbers or yield? The yield will depend on the wattage you have on the plants, not the number of plants themselves when dealing with scrog. You do want enough to fill it up, but not so many they will crowd each other.
This is based on research, not on any knowledge of my growing.
A true scrog would be as few plants as possible to minimize potential legal ramifications,so 1 or 2 depending on your lights. I scrogged 4 in a little under 9sq ft. Next run is 6 in that space and that's cozy.
Power of your lights, container size, desired crop cycle length, environmental control abilities, lots of things affect number of plants. If your not worried about how many plants you have then just run a clip n flip sog and don't mess with the hassle of a scrog.
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I used to scrog everything and I built a setup of eight screens to fill my flowering space. Four screens per 600w light - each screen is 24"x19". A total of 26 square feet of scrog...
I don't scrog everything anymore. But that size screen/plant has worked out well for me.
In your space if you aimed for four plants in 10--15 gallon pots you'd be at a good size i think. Not so big that they're awkward to handle. But still big enough to be worthwhile to scrog.
A scrog screen is simply a tool that helps you spread the plant out to maximize space under the lights. Not much magic in it other than that. And I find it most useful for certain strains that tend to be unruly and floppy. A screen makes a great bed for lazy buds to lie on.