AWS shipped IAM Principal-Based Cost Allocation for Bedrock back in April. The pitch is that every Bedrock API call writes the calling IAM identity (user or role) into CUR 2.0, and Cost Explorer can filter and group by IAM principal or by the tags on the principal (department, cost center, project). It is the first AWS-native way to attribute Bedrock spend below the service line without standing up a separate endpoint per feature. I have been reading the docs and the marketing copy makes it sound like a free upgrade. The fine print is less clean. Three things I want to validate with anyone who has actually turned this on: CUR file size. The docs say enabling principal data splits each cost line into one row per contributing principal. If you have a single Bedrock service account serving ten internal teams, the line for that month becomes ten rows instead of one. For folks landing CUR in Athena or Redshift, what is the real query-cost delta you saw post-enablement? Did you have to revisit partitioning?…