The author remixed this model.
The original drywall grid is good, but cannot print well after its sliced as it tries to do little rectangles since the grid is all in one plane. This often ends up with nozzle on printer picking up adjacent sections and failed prints. With this model, the grid lays out in 3 layers with the perpendicular tracks running on alternate layers, allowing the tool head to operate continuously and minimize chance for nozzle to ruin print.