Maybe I'm missing some context here, but can't you generate X number of presigned URL's with your chunk size and if you provide the chunk ordering it's automatically done on S3 side, but I though you could manually implement the chunk order assignment also.
I would suspect the team making this tool is not exactly the same team maintaining S3...
So adding "server side operations" would require work from the other team to be added.. which certainly could be done if they decided it was needed.
As a first MVP release this project seems neat for read use cases.. and feedback from the community can help ensure read operations are solid while they are also working on the write side -- which they admitted was lacking in this initial release, but want to improve.
