resized images

It seems unclear for existing images whether the optimizer changes the
* thumbs generated by wp media
* crops/feature images generated by theme

these would all live in the same directory as the image

It appears the thumbs generated by wp media are only touched in the bulk opt, not in the single image opt.

Will the Optimize Everything Else keep a DB so previously optimized images will be skipped?

https://wordpress.org/plugins/ewww-image-optimizer/