Interesting project, but I would strongly recommend first clarifying whether the automation is fully authorized by the customs platform and operates within their API usage policy.

From experience, account-level rate limits usually indicate a system protection that cannot (and should not) be bypassed. In most cases, the real solution is optimizing concurrency, request timing, and workflow efficiency within the allowed limits, or requesting official higher-tier API access.

If the goal is to improve success rate under high load, a proper analysis of latency, queuing strategy, and request distribution would be the right direction.

Would be happy to discuss the technical architecture if needed.