Thats net looks good, think and white, would use it. Especially for space management, they banging and will be hard to have enough space for them all later. You can also bend stretchy stuff under it, but it will stretch regardless of your net. I would still use it as an indicator for your prefered height. Bending i would thread or clips. But with your light setup its also okay if they outgrow each other, since you can adjust 2lamps completly different. I would let them grow and defoliate high growth a lot. Think thats better than keeping them low, You can check my dairy im in the ame situation, few week ahead.