bigquery-api-go-client，bigquery流插入延迟

Is there an optimal way to improve the speed of requests to an insertAll request via the golang client?

My current structure is such that:

1. Rows get submit to a queue
2. Upon hitting job size, a new job is queued up (approx. 250 rows)
3. A worker picks up a job from the queue
4. Worker formats + sends insertAll request to BQ

The above works fairly well, however I seem to be having an average of 8-12 seconds per 250 row request.

I should mention that the number of workers being used is generally 200, however I have tried higher / lower values and it does not seem to make much a difference (higher usually seems to take longer per job).