Add a checkbox to the S3 section of the settings page labeled “Use vanity domains”. Selecting that checkbox would cause URLs from the image uploader to have the form:
We’ve used S3 extensively, and have found that some of our customers cannot access content on s3.amazonaws.com - their corporate firewalls disallow it.
However, if we use a vanity domain, those same corporate customers can see the files.
We’re absolutely loving the work you’re doing - thanks!