I cannot comment on this Azure-part, although it seems odd that Azure would not support per-file access configuration. That should be doable with S3.
Yes, for now, one tusd instance per destination (e.g. Azure container, S3 bucket, file directory). Since many people ask for this, we will change this in the future, but there is no schedule made yet.
indeed, this would be an interesting feature, as we also plan to use different azure containers dynamically behind a tusd-server depending on the upload metadata.
Thanks for the feedback. We don’t have any plans right now to add support for multiple storage configurations in a single tusd instance, but we will keep it on our radar.