Problem is the Boto-Rsync creator himself moved to aws-cli (as you can read on the project's issues thread at github.
And s3cmd is far from stable (at least on my VPS, my mac and my raspberry).
But the main reason I need aws-cli is the hability to --delete-before on a sync job. On my project I always need to first clean the precious space of my raspberry sd, and then, download/sync the files with the bucket.
It is out of my understanding to modify the aws-cli code to work with dreambojects endpoint. Maybe a power user from this forum could fork it.
Btw, if you know how to make these other tools, boto/s3cmd to first delete, then sync/mirror, please advice me.