How to include MEXP into Featured Image and ACF Image Fields

This is an awesome project! We made our own tab and have assets feeding in for the WYSIWYG Add Media button, the only issue I was wondering about was how to extend the same functionality to the Set Featured Image button, and ACF Image Field button. I currently have our assets showing up when you click on Set Featured Image by making some modifications in our service's js.js by extending backbone and using `media.view.MediaFrame.Select = select_frame.extend({` to enable it on the Set Featured Image button, but when I try selecting the asset, I cannot seem to get it into the featured image (basically, I just need the steps to add an attachment ID to the featured image area when an asset is selected; I know I must download the asset and import it into the media library, then attach that attachment ID to the set featured image area). If anyone has any insight on this, it would be great! I am currently trying to understand backbone.js to make this happen.

Start with the service's js.js and the media.view.MediaFrame.Select extension described in the issue. Trace the Set Featured Image flow and the ACF Image Field entry point; no test or target file is named. Done would be a documented, verified path for selecting a Media Explorer asset in those fields.

Written by the indexing model from the issue text.