Author here: commented here about how you can use async inserts if that's your preferred ingest method (we recommend that for batch).

https://news.ycombinator.com/item?id=45651098

One of the reasons we streaming ingests is because we often modify the schema of the data in stream. Usually to conform w ClickHouse best practices that aren't adhered to in the source data (restrictive types, denormalization, default not nullable, etc).