Use 95A TPU not PLA. Offers good protection and it looks nice. You may need to tune your retraction settings for less stringing and make sure to dry the TPU for best result. Little to no post processing. Supports are required. I used Apple's Accessory Design Guidelines and Autodesk Fusion 360 to design the case.

Files attached:

iPhone 13 3D Model (stl, step, f3d).

iPhone 13 Honeycomb Case (stl, step,f3d).

Printing profile (3MF file) for those printing with BambuLab A1 Mini. (it needs some tuning for perfect results).

For any questions or problems, contact me.