S3 bucket to uploads

Is it possible to use the S3 type filesystem so that the entire upload folder uses that type of disk?

Howdy! Using S3 as the filesystem wouldn’t work for the WP media library. You would need to use something like https://github.com/humanmade/S3-Uploads to get the media library onto S3.

Agreed, I am currently in the process of setting up the S3-Uploads plugin too.