Why are you letting a plant get rootbound?
So feed it more!
We have had solo cup challenge runs and I've seen over 2 ft tall plants is solo's, and their doing just fine. over 4 ft tall ones in 1 gallon pots, etc,etc.
It's all about how big you let it get before flowering. Simply use the right pot for the size you plan on running.
Cloth "air pots", Meh, I tested those for a certain company before they released them. I told them they suck (basically). Because they make the root grow into this super dense "ball" in the center of the pot. This is surrounded by an area of unused media. If your doing organic water only soils. Your loosing aorund 30% of the available nutrition in that spoil, by it being unutilized by the plant.
Not to mention that you water this super dense ball and you get an "umbrella effect". The water simply runs over the root ball and much of it goes right out the sides of the pot. After this test run, I cut a root ball in half after a watering. The center of the "root ball" was dry.
You sure don't want to let the pot sit in the run off and soak it up, or at least you shouldn't.