if i remember right your scrogging a single plant, iv scrogged a single plant and a 6 plants in one screen, i didnt add the screen until they were moved to my flower space, when i added in the screen i set it low enough that it filled about 2/3 of the screen, the first 2 weeks of 12/12, the "stretch" or transition phase fills out the remainder of the screen, so i guess the point im trying to get at is usualy you add the screen when its flipped, grown to the right size in veg you can fill at least 50% of the screen once flipped to 12/12 and the first few stretching weeks will fill the rest, if you fill the screen while in veg then theres no space left to tuck the stretching/run away branches, granted it fills the screen but thats not the point, the screen is used to help keep the canopy lower and even, so what should be 5ft+ plant is crammed and spread out under 3ft so lower branches arnt wasted and get the chance to reach the canopy. at this point i wouldnt really worry and just keep tucking runaways under the screen, may take some adjusting but do what yah can to keep things as even as possible and you will be just fine and should have a good yield.