I'm sure incremental is the plan, or he wouldn't be starting in the majors. He's got enough on his plate (becoming a better CF, handling major league pitchers) without doing a major mechanical overhaul in spring training. As some have previously said, he might have to fail first before he realizes it needs doing. But you could say the same about established players.
If his defensive ability catches up to his raw skills and his floor is just, left-handed Harrison Bader, nothing wrong with that either. But not what we're dreaming on. (We not only want an All-Star in the future, but a PPI bonus this year).
Hopefully he does well enough that he doesn't get sent down.Truth is that happened at least briefly to every successful Phillies prospect of this era (Bohm, Stott, Crawford, Rojas) as well as the less successful ones (Moniak, Halseley, Kingery).