Alter all images styles to add a particular effect before all others? I just downloaded the manual crop module: https://www.drupal.org/project/manualcrop

It must be added as an image style effect before it is applied.

I would like to apply it to all image styles before others are executed.

Is there any hook_preprocess_image_style that can add an effect to the stack before others are processed?

Or anybody have any other good ideas about how to do this programmatically other than manually adding the style?

Thanks!
Yes,  you can do this with hook_image_styles_alter.

I'm not so sure it's a great idea since you'll be enforcing adding your effect no matter what the user might try to configure via the interface, but it will definitely let you do what you want to do.