From the release notes:
Non-Bulk Mode Available
8.3 With the following contribution you can now configure the importer to work in non-bulk mode, which is a bit slower but allows regular Work instances to be created and directed to specific queues:
Nuxeo Importer Without ES Indexing
8.3The nuxeo-importer can now run with Elasticsearch indexing turned off. The reindexing can be done after the mass import.
This should be added to the Nuxeo Bulk Importer documentation.