Default false. Adds a nested research object to book rows: edition/work identity, publication, series, work-level rating and text-review language counts, and CSL JSON references. Uses source-bound public facts with no extra item fees. When includeReviews is explicitly false, qualified first-party metadata can supply all research after one anonymous bootstrap per run; otherwise the established page route is used within the same limits. Missing or incomplete source data is explained. Use JSON export to retain nested research; existing overview columns stay unchanged.