Please keep in mind that the “merge” aspect of the Split-Merge Block is where the contained jobs are downscaled rather than all the event messages being combined. This means that you can output a single success or failure message from all the jobs run by the Dynamic Workspace action.So, in order to create more detailed reports of all the combined jobs, you still might need to follow the Dynamic Workspace action with another workspace purposely built to compile that information. This kind of workflow is shown in Output Port Behaviour examples.
As an alternative, you can also request information about an Automation from the FME Server REST API. With different endpoints, you can fetch the Automation log file, specific types of messages, or statuses.