High-Res 3D Model PNG Exports

I have a collection of completed Blender 3D model files that simply need to be rendered out as 300 dpi PNGs on a fully transparent background. The final size for each image must be 3840 × 2160 with crisp, alias-free edges and colours exactly as they appear in the original files. No modelling or animation edits are needed—just open, adjust the output settings (RGBA, 300 dpi), adjust the camera so it is exactly front facing (front to back flat), and export. If there are multiple variations of textures, I need them exported too.

Please return:
• A PNG for each model, named to match the source file
• The updated .blend files if you changed any render or compositing settings

Let me know how quickly you can turn this around and if you foresee any issues.