I lowered my light wattage from 480 to around 300 ...

Finally figured out this question wasnt about these plants lol So it's pretty to calculate how many watts you need for your 4x4, but basically that number is 300 true watts. So you're actually golden as it is. I actually turn the light down last few days of flower to promote terpene creation. So to answer you're question on what happens with not enough light : a photoperiod could reveg, grow slow, not buff out or start drooping then yellowing and wilting. If you see any of those signs, it's "already too late" in the sense some damage has been done but it's not un fixable. Hope this helps Mota ! 🚀