Inverted pinch tool

While playing with the pinch tool, I realized that there's no way to get a perfectly symmetrical pinch with no door cargo bay pieces and still have an open space between them since the pinch tool only works in one hemisphere of the part. I propose adding an inverted pinch tool (pinch top/pinch bottom) to give us more intricate control and freedom with the shapes that we can create with the tools provided.
To clarify, I'd like to pinch in the normal direction as well as the opposite direction to create the illusion that the part is pinched on both sides without having to make bits of it be invisible to appear as though it's open space.
If that's confusing I can upload a picture to better illustrate it