@SteveW3592 thanks for pointing us to the original discussion on the forum.

I checked and the documentation still specifies that BIX needs to be able to write records into the database, so while maybe on configuration time you might only need read permission, at runtime when executing the extract the privilege to insert records is needed.

So the documentation mentions the need for generic insert and view-metadata privileges, as well as when client is selecting extract file type. 

"Specify a JDBC URL to an existing external database instance into which to insert the database schema manifest files. You must have insert and view-metadata privileges for the database into which you want to insert the database schema manifest files."

See documentation  Creating and running an Extract rule

I will check internally if the enhancement requests are still open for a change in functionality ( EPIC-20603 / US-99914).