I'm sorry, but based on the information provided in the extracts, there's no direct mention of changing the file format for files written to Redshift via the S3 staging method from CSV to Parquet. However, Airbyte does support exporting data in Parquet format to S3 as mentioned in this [tutorial](
https://airbyte.com/tutorials/postgres-to-csv-json-parquet-avro-in-s3). You might be able to use this feature to export your data to S3 in Parquet format and then load it into Redshift. For more specific information on how to configure this, I would recommend checking the official Airbyte [documentation](
https://docs.airbyte.com) or reaching out to the Airbyte community on their [forum](
https://discuss.airbyte.io) or [Slack](
https://airbytehq.slack.com) channel.