I think Knox is just a young player who needs to continue to develop.
He has the physical tools to be good. I tend to not pay too much attention to dropped passes. These are NFL pass catchers. Guys go through patches of drops sometimes. Knox will get that figured out.
Now, that said, I would get another TE in the draft or free agency to get another guy in the system. I also like Lee Smith as the blocker/attitude guy.
Not everyone is Diggs or Brown or Beasley. We are VERY lucky to have all 3. When those guys drop a pass (which seems like never) it sticks out because it's so unusual. You almost are OK with it, because it means that was their drop for the next 6 games. But as we should know, that's not necessarily the norm in the NFL.