I have never covered my outdoor plants to induce flowering. I just like to let mother nature take her course. But I believe if you were to stop the light depletion to the plants that you have been covering you might stunt the plant. Because it will have to get used to the light cycle that is being produced naturally. But since your plants are so close to finishing I am not sure. The other plants became bigger because they were exposed to a natural flowering cycle not a controlled one. But I am not sure since they are so close to finishing. Good LucK