The lines are anchored to the wall. There's no tension release on that. The gripper in the middle of the room unwinding some line won't prevent you, your child, or a pet from hanging themselves from the anchored end.
A tension limit 28 Newtons means the average child of age one or up is heavy enough to break the line.
Unless you're using tensioned steel wires, I don't think even a child is going to have problems escaping from some fishing line.