Interesting.
We use passing sticks, and I've thought about adding in the QB pressure element. But our completion percentages are pretty realistic, so we decided not to make them any harder.
One thing we did was limit the defense to pivoting only one player to react to the pass. Previously, defense could turn all unengaged players to react.
We also eliminated any defensive reaction if the receiver was wholly within ten yards of the LOS and fully between the numbers, in order to make throwing short over the middle possible. It did do that, but we are going to tweak this rule. On old fields especially, there's a LOT of grass between the numbers. One thought is defense can pivot one defender to react when the receiver is in said zone, but he has to be farther from the placed ball than the receiver is. We're still thinking about it, and any suggestions are welcome.