There are some errors with Collapse in BehaviorTree :
-Collapsed node doesn’t update childs positions on a drag and drop.
-Collapsed node doesn’t copy all their childs when the user copy the collapsed node (wich is counter-intuitive).
I just tried to confirm and child nodes of a collapsed node do move along with the collapsed node when you move that node, as indented. I really can’t reproduce a case where this does not happen as it should…
Regarding copying a collapsed node, I will take a look at including the children when copy/pasting, yes. You can of course “duplicate the branch” through the context menu, but I agree that including children when node is collapsed is better.