The freshman year of study is pretty rigorous. It could interfere with the players main goal of preparing for the draft.
Brey has said he is open to one and dones but it has never struck me as a good fit.
Stewart is 6'8" 240. I don't know how much his game has grown but when I saw his film he was strictly a down low force who was very mobile. My bias is one and dones have more height for down low guys. He apparently has unusually long arms though. That could make up for height difference like it did for Bonzie.