Explain the design of the 80req/m limit and 15.5k req

Hello, can you please explain Step 5: Load test? Specifically, the configuration is for 80req/m. I checked the application.yml file and found its limit is 300/m. In addition, can you explain more about the 15.5k req because when running this step, I see nearly 4k messages sent, there is no information about sending 15.5k req (I see about 15.5k req on the service bus in azure but I really don't understand why). I look forward to hearing from you and it would be great to receive an explanation from all of you.