I generally agree that, ideally, he's not your every down workhorse back. He's a satellite back who you can put in for occasional run plays and you can also plug him in as your slot receiver.
The issue is that he's so clearly better than Crowell that I think he needs to be getting more of Crowell's reps. If we had a better back, I wouldn't be opposed to Duke becoming the receiving down back and spending other downs in the slot.
I do think that Hue needs to figure out better ways to get Duke involved regardless, though, because he's so clearly our best offensive player right now. When you've got a guy who makes positive contributions damn near every time he gets the ball, you need to get him the ball more fucking often.