I love Michael Mayer. But after watching him the last couple of games, he does have a bit of stiffness. He needs an extra second to start after stopping. It does not effective his overall route running, but it does affect his explosiveness. He was a bit nimbler as a freshman when he was under 250 pounds. I think he's playing a little too heavy at 265, but I think the plan for that bulk was to help a bit more in the run game. When he gets to the pros, whatever team drafts him will probably ask him to drop some weight.
I am sure a few on here won't like my comparison, but he looks more like Dawson Knox than Travis Kelce.