Smush has amazing potential...unfortunately its not following wordpress framework standards...which is against the wordpress code of conduct...making it not play nice.
Specifically its not playing nice with the Amazon S3 plugin, a wonderful plugin, compatible with everything done in proper wordpress coding standards of using the wordpress functions.
Amazon S3 works with the native cropping and image editing functionality of wordpress seemlessly...but not with smush...meaning smush is not following the rules.
This is a serious problem as it means other issues may be lurking unforeseen where it will become incompatible. Its probably something small, can we forward this issue to the dev so he can possible replace one of his php functions with a wordpress function and get it all working!
Please advise on his/her response.