If you are already in 7gal bags and the plants are big (how big?) then you may already be limited to 4. I don't think you are filling those bags anywhere near in 4 weeks though, unless I've misread something.
What you can also try, if you have the space is 8. Put four on the floor covering 4x4 space with light covering that print (if the bags/canopy allow it 3x3 would be better) then at either side but two pots raised up on wood/containers by about 1f (depends on plant size, give or take). Those on the outside edge will get good side lighting especially if on 3x3, like a make shift stadium setup. It works well, if you have space. The side ones ofc won't yield as much as the central plants but as an estimate, maybe 1/2 to 3/4 max of what you get from the main ones. It does require open hood and canopy temp control though. If you are open hood you can try to drop your filter down online to the end of the bulb (filter sleeve facing the bulb) so that it can suck hot air directly off canopy.