WFM Bulk Scheduling API 429 errors during JMeter load test

Could use a hand troubleshooting this rate limiting issue with the Workforce Management API. Running JMeter 5.6 on US1 environment. The goal is to validate capacity for bulk schedule uploads.

When simulating 50 concurrent threads hitting POST /api/v2/wfm/schedulingschedule, I get HTTP 429 Too Many Requests after about 200 successful requests. The response headers show X-RateLimit-Remaining: 0. I am aware of the standard rate limits for WFM endpoints, but the drop-off seems too aggressive for a beginner load test scenario.

The JMeter config uses a constant throughput timer set to 100 requests per minute. Each request contains a valid schedule object for a single user. No complex dependencies or prior API calls. Just direct POST requests.

Is this a hard limit for the scheduling endpoint? Or is there a specific header or pagination strategy I should use to avoid throttling? The documentation mentions burst limits, but does not specify how to handle sustained load for bulk operations. Any tips on adjusting the JMeter thread group or API payload would be helpful. Trying to understand if this is expected behavior for Genesys Cloud WFM APIs.