[WP Smush Pro] Smush Pro for Offloaded Files

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!