What I am wanting to see here is a good explanation of how we can recognize that while an extreme of a good may be unobtainable, a lesser amount of that good is definitely desirable and working hard to get, and any formula we develop has to take that into account.
Cassius this doesn't give you the answer you're looking for, but there doesn't seem to be any formula other than frank speech. The line between N/N and unlimited desire, as far as I can tell, is so individual that it can only be dealt with on an individual basis, like medicine. People needing to depend on formulas might be better served by the Stoics (except that they would then lose the benefit of a coherent worldview).