Idea in a nutshell: Height of the Window/ Opening that makes Area Boundary snap to it should be up to the user to decide and customise.
As it is now:
If: A window/ opening Height is more that 1189mm ,
Then: In a Rentable Area Plan, Area Boundary will always snap to the window.
Because of this behaviour using Area Boundary Rules is mostly unusable outside USA/ BOMA territory.