Pass through custom aspect ratio to image editor/Dashboard UI

Problem/Motivation

I have a slideshow that uses Drupal Image Styles to have a consistent aspect ratio. Instead of autocropping and resizing, it would be nice if a user could click on the horizontal crop icon in the uppy dashboard UI and it would use a custom aspect ratio that fit our needs. The preset cropping options don't exactly fit the cropping needed for our slideshow, so the image gets cropped again by the image style.

The only hook in the module I saw is for locale mapping to change UI strings. Could or is there a way to add a custom aspect ratio for the crop? Any help is appreciated. Thank you!