I wish I could remember the members name but we had a that grower that only used one gallon pots and solo cups. it would blow you mind how many plants he ran in a 3x3 or maybe a 4x4. I had considered it at one time just to get through my seed backlog which is out of hand ATM.
I have pulled an oz a few times in a solo with the right genetics. Hoping not to embarrass myself in the seedstockers grow. I have not been practicing for a few years and the overall aptitude for that style of grow has gone up exponentially in the community.