I agree with your take on him. I think he will end up a good possession guy at the least and replace one of Woody/Kupp. How each of them plays this year will decide who they keep IMO, and that's assuming that Jefferson at least takes a small step from the guy who was showing well in the playoffs last year.
But he has the speed and the route running talent to double move some corners and roast them. He did in fact get open deep for us too but wasn't targeted. I think he has more to give and maybe this staff can get it out of him, get him to fully tap it basically.