This model prints well with PETG and just 3 layers at 0.3mm layer thickness does the trick. The grid comes off just stiff enough and bendy to be inserted into wall and snap back to flat.
A brass wire or screw can be attached to grid to prevent it from falling into the wall while installing. Using some power grab or construction adhesive after its inserted into wall is easy to do by moving the wire or screw attached to grid around. Then pull on the wire/screw and tie off to a piece of cardboard or wood from front of wall and allow glue to dry overnight.
Then remove wire/screw and apply spackling patch in 2 or 3 applications and allow the spackling to key into the grid for a solid patch.
This worked really well on my textured wall where I did not want to cut out a rectangular patch and back it up with wood and new drywall. No amount of texturing would have been able to hide straight cut lines. This patch let me keep the opening organically shaped and a bit of scotch brite pad dipped into spackling mimicked the texture good enough.
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.