The restore command can restore several backends at once and checks whether the given backends are activated, exists or supports online / offline restore (depending whether we call the restore task or restore tool). This enables to fail fast and to avoid some partial restore (some backends restored while some failed to be).
We may enhance partial restore prevention by adding other verifications such running a dry- run. Nonetheless, performing a dry-run may be costly with big backups (several To) because dry-run unzip the archives. As consequence, we may implement internally a "light-weight" dry-run that would perform all the non costly operations of a dry-run and add this light-weight dry-run to the checks that prevents from partial restore.