He had good progress under his former owner, but one position training is of course a great starting point for future stardom :-) I'm not sure he has the height to progress quickly enough as a SF, but then again - we are lacking good SF's. I would start with leveling him out, that is improving his range, handling and passing to something close to his other outside skills (level 8-9). Then start working him as a SF if that fits your training regime, with further improvement of inside defending and rebounding as focus.
At 19, he is still a season away (at least) to make the U21. My point of view, that is...