We've smushed our entire media library, but I can't find a way to include images that were created by Soliloquy slider. Soliloquy creates its own custom image sizes for the slider and saves them in the media library folders (wp-content/uploads/year/month). However, they're not viewable within the media library itself so I guess they're not visible to Smush.
Is there a way we can include these in the bulk Smush please? Soliloquy creates images in the format: "samefilenameasoriginal-1600x650_c.jpg" and saves them in the same place as the original.