I modified MonoManager.cs and deleted the Update method, and added a public Tick() method with the same contents.
I manually run MonoManager.current.Tick() from BehaviourTreeOwner’s Tick(), just before the BehaviourTree’s Tick().
Do you think there is a more elegant solution? Are you planning to support Turn-based games? I rather not modify your code, althought these are very small changes.