It probably won't help you much at this point, unless you are able to do it immediately, but definitely look into a taller tent. After hangers and getting some space between light and plant, 4 feet doesn't leave much room at all. You would probably have to rush every flowering stage and keep all the plants relatively small.
Amazon has a massive variety of grow tents and you can buy a 2x2 at 55 or even 64 inches. (Quality of the tent varies, but I'm never too disappointed)
That extra 16 inches could, and will, make a huge difference.