WFM Schedule API 429 during JMeter Load Test

Having some config trouble here… Pushing 100 concurrent threads to /api/v2/wfm/schedules on Genesys Cloud US1 via JMeter 5.6 triggers HTTP 429 errors immediately. The environment uses standard rate limits for workforce management endpoints. Logs show rapid throttling despite exponential backoff in the script. The target is to validate capacity for bulk schedule imports. Why is the throughput so low for this endpoint?