It seems that most of the drywall mounts that I looked for printed in a vertical orientation, which is not good for strength.
For once, I didn’t reverse engineer anything to design this. Lulz.
https://www.printables.com/model/548516-printable-drywall-mount
Update 8/10 - Added dimension sketches, Added .step file, Added a thinner support ring option that will sit more flush (but not completely)
It’s probably limited to the thickness of the drywall. All I needed was a lightweight shelf and maybe a picture or two. I would have to test it to get some real numbers.