The larger sizes 6" and up are best for giving a plant something to anchor itself to. You would have to top feed them until the roots showed on the other side. I always use 6" used a 4" last run and it actually crashed through the lid and was difficult to get back on the right side is why I'm sticking with 6". I grow pretty large plants though and a 4" or smaller could work for you, if they get heavy you can always anchor them in another way. Sorry not a clear answer maybe @trojangrower can help he does some areo experiments.
I use 3" atm; that's the smallest I would go. aeroponic-model-4z0-stoner-experiment-5263199-rev_3-a.2866132 I'd recommend going larger if you plan on growing monster plants. they have wider rimmed netting pots now that would prevent this.