We haven't tested write-only or read-only buckets and as such S3Drive requires both write and read permissions to function properly.
However if app works with limited sets of permission for your use case, there is no harm using it like this.
Even though we're designing app so it requires minimum set of permissions or operations for its functions it may happen that some feature might not work properly in the future.
E.g. if you upload a file, the existing file would be overwritten, if versioning is enabled the previous version would remain restorable however if versioning isn't enabled the existing file version is lost.
In the future we might actually perform read first in order to display prompt to the user to ask if they actually wan't to ovewrite the file.
Such read would've failed if there is no read permission to the bucket, so we would have to fail gracefully in order to not break things in your case.
Our aim is to not break workflows, but if by any chance it's not easy/possible to implement such graceful failure handling we may be required to prioritize features based on app standard usage.
