SubD levels are one consideration, but as far as how detail is applied, there are multiple philosophies on this. Personally, I'd like to see something you can adjust - dial up the SubD when the figure is close-up so you can get those details, but dial it way down when the figure is in the distance because details no longer matter.

Or better - yet... how's this for an idea: Unreal Tournament ('member that game?) did the de-rez thing for its meshes programmatically in the Unreal Engine - close-up figures and objects had oodles of detail so it all looked (for the time!) nice and realistic, but far away figures were un-SubD'd (is that a word?) as their distance from the player POV increased, in order to take pressure off of both the CPU and GPU (they did it so that the framerates stayed high and game play could remain smooth).

Maybe Poser could do something similar? Figures could automatically lop-down SubD levels (or fractions thereof) as their distance from the camera increased? This would of course have to be calc'd between the "render button pushed" stage and when it gets handed off to the render engine, but it seems doable. Given that the tech is at least 20 years old, it shouldn't be too much of a burden, or increase overall render times by much (in fact I daresay the time savings from the actual render process would more than offset any additional time taken to rez-balance a scene in preparation for rendering...)