I would have given 5 stars if it converted to PNGs without any quality loss.
When I convert a clean WEBP (no artifacts) to PNG, the resulting file will show artifacts, this shouldn't be happening with a lossless format.
Even if it's technically possible to create a lossy non-standard PNG with reduced file size, that shouldn't be the standard way, if that't the case I suggest an option to change this behavior.
