Mysql 8 rocksdb engine csv loading performance

Our system copies around 10B rows (each rows consists of few numbers) every day from Big Query to Mysql, the rows are fetched later by primary key (key-value style queries) with 10-20K reads per second. Ingestion process exports the rows from Big Query to CSV files and load them to Mysql with rocksdb engine (which should be write-optimized) with guidelines according to

Current benchmark on 16 Core / 84GB RAM server shows CSV load speed of 150-200K writes/sec which is not enough. The bottleneck is in the index creation (loading without the index is much faster).

Any ideas how can that be improved?

Can you share the schema of the table and the rocksdb variables you have in your my.cnf