I’ve added an UpdateMode in MonoManager for the next version soon to be released. I didn’t create a FlowScriptManager, since MonoManager is used for that. So I’ve basicaly went with a similar to your “0.1, 1, 2.1” suggested approach.
By the way, depending on your use case maybe the use of StartBehaviour/StopBehaviour in the FlowScriptController can suffice.