I have not been able to make very much sense of how the meshbuilder budget works, but if the ring is only defining mesh detail within a certain radius, everything left undefined may be left with no detail at all. For some view distances this may not be a problem, and even desirable since resources aren't being wasted providing detail to areas behind the fog wall. In my more recent experiments with expanding the visible area, it would be important to make sure that the full area has one or more rings defining it.