yes, as soon as people start to get used to it and how to quickly place with hotkeys it will be sooo abusive. They are like supersize dragon teeth that can be placed at an enormous distance form the constructor.
I'd like to see a special option that would lock the maximum selectable height difference to exactly the height you need to stop a vehicle from passing over it.
Or some predefined blocks of terraform with that same minimum height and minimal width.
Or a predefined square shaped terraform block you can place on top of a tank to lock it in.
Such a blocks won't cost more than 75 metal and can stop a 650 metal tank.