The heavy duty 84 tooth gear is a good addition to the VEX arsenal. I got used to the coordinate hole pattern of the original 84 tooth gear and find it more flexible that the circular pattern in the new gear.
If any more items are introduced please consider the coordinate pattern. Also the original had counter bored recesses for the screw heads on one side and flush posts on the other, flipping the gear gives the builder a choice. My dream gear would have some recesses to accept hex nuts and a few holes sized to be self threaded like the trucks on the sliders. These would be distributed in such a way that flipping or rotating the gear would provide as many combinations as possible.
I realize retooling an existing product may not be feasible, but please consider for any future items.
If the large sprocket is retooled for the heavy duty shaft please consider the above.