Behavior Tree Injection

I have a few questions on behavior tree injection:

  1. What’s the difference between RunBehavior and RunBehaviorDynamic
  2. Once a sub-tree is injected and have return some result (fail, success or in progress), does it return to the parent tree?
  3. If it does return the parent tree, if I want to remove the injected branch after single execution, is that possible?
  4. If 3 isn’t possible, what can I do to make it possible?
  5. Is it expensive to inject subtrees?

Thanks!