>> "Unfortunately, on our final testing with the S3 bucket, we encountered an issue: "The authorization mechanism you have provided is not supported. Please use AWS4-HMAC-SHAS256.""
This is fixed in our development branch, we don't have a beta version of the next wyBuild out yet. In the meantime you can upload you updates using any 3rd party uploader (like Cyberduck: https://cyberduck.io/?l=en )
As far as downloads go wyUpdate only supports real protocols (HTTP, HTTPS, FTP, and FILE). It doesn't and won't support proprietary methods to download updates.