Your plants are certainly growing very evenly from plant to plant That's incredible, usually they vary in dimensions. I think a net across those would work out very well. Occasionally if you want your plants to grow up, you can raise the light so they'll stretch to it, however since they're autos, I think if you just give it a week or 2 they be zooming up before you know it.
They look incredible already for 4 weeks. :)