Restore GSI backup to a different bucket.
restoreIndexMetaData ignores the HTTP argument
Restoring GSI data to a different bucket using cbbackupmgr is roadmapped for Cheshire Cat.
The restoreIndexMetaData REST API is not currently documented.
The documentation for cbbackupmgr restore already states:
This option will only restore data to the Data service and will not restore the metadata for any other service.
Postponing this issue until Cheshire Cat.