Webflow already has the ability to minify CSS, so why not minify JS? I see that this was mentioned in the forums over a year ago from a Webflow staff member. We already know that CDN hosting is fast, and I'm NOT talking about the user experience. This is simply an SEO consideration.
Also, enabling compression on JS files, including the modernizr script should be considered. There is an article here about how to serve compressed files from the CDN, http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/ServingCompressedFiles.html#CompressedS3