I just read the article "What's New in ArcGIS Workflow Manager 10.9" and would like to know what tools exist in the ArcGIS Pro SDK to communicate with the WFM Server (to inquire about the status of the JOB, to command the execution of a step, etc.)?
At the moment there is no Workflow Manager Pro SDK for communicating with the Workflow Manager Server, it is something we will be investigating in the next release (the one after 2.9)
Could you let me know specifically what you would like to have access to, what you would like to be able to do? That will help shape our planning.
From your comment it sounds like you'd like to be able to get and update job information and run steps in the workflow. What else would you consider your minimum requirements?