Maybe there's a way to handle this already (I've been looking around and couldn't find it) but it would be WONDERFUL for a way to run SMUSH Pro on images after they've been offloaded to a remote server.
Example: I have a fairly image-heavy site on WP-Engine and they made me use their LargeFS service to host them on an Amazon S3 bucket. Unfortunately, this was before I got my WPMUDEV plugins installed, so while *new* images get properly smushed, I have a vast library of older images and apparently no way to ever optimize them. With the other plugins and tweaking, my Hummingbird stats are all 96 to 100 … except for "Optimize Images," which just barely cracks the double digits.
I'd love to get the benefits of optimized images on my offloaded files, too!