Low AWR - yeah, especially if it impacts general adjusting to the pass. We've seen how WR sometimes don't adjust or come back to the ball and allow an INT or don't fight for possession on a tight pass - those situations being impacted by AWR and maybe coverage abilities (with a much lower threshold of course since no WR is apt to have an 80 MCV or something) or PRC (might be best).
And on jump ball situations - it should pretty much always happen if the WR can see the ball and is able to get to it. When I see a DB go up for the ball in a jump ball and have it and then get insta-tackled, it just makes me wonder - could he have broken it up?
I also like the idea you mentioned with defender's hands on the ball being a trigger. Or if ball is X distance from a defender, increase the WR's aggression going for the ball - which makes more contested situations if both players are reasonably close.
Might also create more opportunities for interference calls between aggressive players and contested positioning.