Hello! The target use case is integration testing, verifying that your application calls the right operations with the right data, not production fidelity. For that, MiniStack works well and is free. For anything requiring exact DynamoDB behavior (capacity throttling, consistency window, stream processing), you're right that it's not a substitute. Contributions to improve error fidelity are very welcome (we have pending ProvisionedThroughputExceededException, TransactionConflictException, ItemCollectionSizeLimitExceededException)