Hi RoughTiger69
I'm actually not sure about DVC support as well, see in these links, syncing and registering is a link, not creating an immutable copy.
And the sync between the local and remote seems like it is downloading the remote and comparing to the local copy.
Basically adding remote source Does not mean DVC will create an immutable copy of the content, it's just a pointer to a bucket (feel free to correct me if I misunderstood their capability)
https://dvc.org/doc/command-reference/remote/modify#available-parameters-for-all-remotes
https://dvc.org/doc/command-reference/status#comparison-against-remote-storage