throw...if a WR can make a play on the ball by adjusting his route/pace then he absolutely needs to do that.
This isn't a Jake Retzlaff specific thing...Jaren Hall underthrew probably 90% of the deep balls he threw. But his WRs attacked the ball and came down with it. Darius and Chase do the same.
If you're a D1 P4 WR you've got to have the skill set to catch non perfectly thrown balls, because the QBs at this level aren't going to be dropping dimes 40 yards down field every time...they're at least throwing catchable balls even if they aren't perfect.
Different WRs have different skills sets though...I think Kody is dominant in short to intermediate crossing routes but probably shouldn't be used in go routes. We have guys like Roberts, Lassiter, and Phillips who really excel at those go routes and they can be trusted to make a play on any *catchable* ball, even if it's not perfectly thrown