As of now, cargo-cyclonedx explicitly creates sub-components for the component entry in the metadata for the respective compilation targets.
This appears to contradict with the suggestions in the Authoritative Guide to SBOM, that states, that "The SBOM should have a single bom.metadata.component without subcomponents".
This has the consequence, that generated SBoMs currently cannot be properly processed by third-party tools, e.g., Dependency Track.