Hello Elliot,
I am also trying to figure this out as I use ACF a lot and have many front end submission forms that I have to manually download image/audio/video and reupload to make work. Gravityforms uploads to its own folder by default but there is a plugin that allows images to be added to the Media Library: https://wordpress.org/plugins/gravity-forms-advanced-file-uploader/
What confuses me is that I can see under the URL of the image as the meta value listed with the correct meta key when viewing the custom fields section. However when I hit publish that custom field disappears from the backend and the image does not display on the front end. Can you give us any hints as to how we can make this work?
Ryan
