First off, to install this you need to change the name in the zip file from ImageOptim-master, to just ImageOptim.  After that when you hit install on it, it takes forever for it to come up in it's configuration menu, I assume because it is processing all your images.  Next, I have 31208 results it comes up with, I don't think there is a chance in hell I'm going to click on these individually to re-mush my sites images!  So, getting the 'generation by lot' thing going, is going to be  a must to make this a  practical module.  Its a good idea though, keep working on it.  These are the results I got on the one image I did do...