Questions about DIF zones and DTS objects

Ok, I understand that by creating zones in DIF objects by using portals it means that only those zones within the DIF that are visible are rendered.

But what about the DTS objects that are placed within those zones in the Torque mission editor?
Are only those DTS objects within visible zones rendered?
What happens if the bounds of the DTS object is slightly imbedded with in a DIF brush that forms part of the zone boundry?