Oh, I don’t know. Things like
1. Can he block big, athletic defensive linemen?
2. Can he catch the ball in traffic?
3. Can he run accurate routes and be physical with contested passes?
4. Can he break tackles and get yards after contact or will he drop like a stone at first contact and then fumble? You know, like he did when he was pretending to be a QB.
5. You said it yourself. He lacks fluidity. Good Tight ends have just that. He runs like he has a rod shoved up his spine. He is fast in a straight line. Nothing else. But he can dunk a basketball. Perhaps Hoiberg can use him