WFM API 429 during JMeter ramp-up for bulk schedule updates

My configuration keeps failing…

Context:
Running JMeter 5.6.2 from Singapore (Asia/Singapore). Targeting /api/v2/wfm/scheduling/schedules. Simulating 500 concurrent bulk schedule updates. Hitting immediate 429 Too Many Requests errors. Rate limit headers suggest aggressive throttling on write operations.

Question:
What is the correct way to handle capacity planning when the WFM API hits hard limits during a simulated load test? Any tips for staggering requests?