I have some questions about what you did : are elastic search index and blazegraph automatically synchronized when you create your items directly in the database without using API or do you have to run specific scripts to synchronize everything ?
After a little modification to my code at https://github.com/jze/wikibase-insert/ the `recentchanges` table is also updated correctly.
Inserted items can be found via the SPARQL interface. You can see the updates in log output of docker-compose. I have not yet measured how long it takes until all inserted items have been written to Blazegraph.
However, the items do not appear in Elasticsearch. For my purpose it is enough to query the data via the SPARQL endpoint. That's why I did not look at the synchronization to Elastichsearch.
Jesper