The pucks are only about 2.5-3" in diameter. When you insert them into the slots there's actuall very little overlap. When I painted my calipers, I had all 4 wheels off of the ground using the pucks and jack stands. There's no problem cus the black area is subframe. Its seem logical that you could lift the car from that area without the puck but I would be very careful about the type of jack pad - I would only lift it using the pucks.
You can see some jacking instructions at the following link:
http://www.cau-llc.com/tips.htm