Your current setup seems complex and large-scale. I can understand that managing NiFi data flow deployment and upgrades in this large-scale setup manually can be overwhelming.

A few days ago, I came across a tool named Data Flow Manager. I explored its website and found out that it offers a UI to deploy and upgrade NiFi data flows. I feel that you can now deploy your data flows without any effort and manual process with this tool.

Also, one of your requirements - scheduling with history and rollback - is also possible with this tool. After reading their website, I watched a few videos where I came across this feature, and it was phenomenal. Means you can record every action associated with the data flows.