The FAR is self defining with regards to the weights which cause you to cross the threshold of applicability.
(i) and (ii) use the term "a payload package"...(iii) states that it is referring to a "...payload, of two or more payload packages". This then defines payload package as a single item. Therefore, if any of your singular payload packages exceed 4 lbs (and the density limit), or 6 lbs, you are subject to the FAR no matter how much your payload weighs.


