Comment by nnunley

Is the main goal here just to have a cool-looking file extension?

Why not use PNG’s built-in zTXt chunks to store metadata? That seems like a more standard and less fragile approach.

I can see the case for using LSB steganography to watermark or cryptographically sign an image—but using it to embed all the metadata you're describing is likely to introduce a lot of visual noise.

Also worth considering: this approach could be used to poison models by embedding deliberately misleading metadata. Depending on your perspective, that might be a feature or a bug.