Here's the Ertz portion of this
PFF article on TEs. Also what they allude to about his ability to get defenders to turn their hips then choose the different direction is what you call an option route which is downright nasty and tough to defend when you have a guy who has that feel for it:
Tier 2: Man- And Zone-Beaters
Zach Ertz, Philadelphia Eagles
As I previously stated, a tight end’s ability to beat man coverage is the most stable metric when grading their potential impact on the passing game. And Philadelphia Eagles tight end Zach Ertz has the second-highest separation percentage (63.6%) against man coverage over the last three seasons. Ertz also ranks in the top 10 in receiving grade (79.6, ninth) and yards per route run (2.05, ninth) against zone coverage during the same period.
He is equally effective against zone and man coverages, where his combined skill set makes him an excellent fit for both schemes.
Ertz is a skilled route-runner who repeatedly wins separation by working to the edge of a man-coverage defender. He consistently wins leverage by forcing defenders out of their backpedal, where he will then work away from the defender as he turns his hips. His success is less about speed and more about timing and how to work a defender with footwork and fundamentals, but he remains one of the league’s best players at the position.