His arm's length will help him at the next level and won't hurt his draft status. We all knew he moved well in pass blocking and pulling on the run blocking. I have seen him in the late 2nd round to early 4th. I would think the 3rd round would be his landing spot unless interior linemen go early.
Watts has the size and length you would want in a 4-3 end and also being able to play the end in the 3-4. He looks like a 6th or 7th-round pick at worst. He has the size and ability to get drafted higher if he does well this week he could be higher as ends who can pressure the quarterback are far and few in between.