Focusing on D League scoring averages is silly. His efficiency numbers are pretty good, although even those don't mean much. Watching video though, you see an ability to put the ball on the floor and attack, as well as hitting a spot up mid range jumper and occasional 3. It's not consistent, but it's there. The free throw % is also solid, which is an encouraging sign. He just needs experience and reps.
D League was good for him this year. Hopefully he'll get minutes next year with the Celts to continue the growth and be a contributor.