This is a work in progress.
I needed to load a battery under the unibody so I came up with this simple part to clip to the backside. This enables me to strap a 1300mah 40C battery that weighs about 109g and shift it's position to get the right center of gravity.
The notches have an overhang so make sure your printer is set up to do overhang prints. I printed this part without supports and just filed the opening down to the necessary width.