To provide a little more information:
To upload from a windows machine (outside our network), we are currently using CloudBerryLab's backup software, CloudBerry is configured to keep 90-days worth of versions. For our internal management we are using rclone.
Based on what you explained, all those extra copies are generated by CloudBerry and not by BackBlaze. That is why rclone reports space usage based on "CURRENT VERSIONS" as BackBlaze is not "aware" of how CloudBerry is organizing data on the buckets -- all those 90 days become the "CURRENT VERSION".
If the backend can't be aware of the difference then we have to get the answer some other way other than a direct query.
The most obvious thing to ask is maybe - does Cloudberry have some way of reporting this by looking at it's own files? (through a mount if needed).
Otherwise we might just need to do it via filtering. Rclone has a lot of options for filtering: https://rclone.org/filtering/
How exactly you do this obviously will depend on the naming convention that is being used, so if you need help with that you'd have to give us some ideas of what the directory structure and filenames look like. Know how often new versions are created (assuming it's on a regular schedule) would also be helpful.