So I have an issue with the cart image cache and I am not sure how to work around it. Wanted to see if you had suggestions.
I host my images on S3 and create thumbs on demand when the requested image doesn't exist. So the 404 hander on the bucket calls my server for the resized image. Problem is that your cache system ignores what is actually returned and stops at the 404 I guess because I get broken images.
I have issues with memory and load during resize else I would always point to my server - it must go to S3 and I really would like to keep the on demand scenario - it's what keeps our server up as we had big issues before generating multiple thumbs.