OP here. You make a very good point. Most of the holes definitely don't need a consistent gradient across every point on the hole. However, some will. The goal is to reveal that underlying nature of the hazards, and this includes contouring. When we get into the really nitty-gritty aspects of contouring's outsized effects on architecturally interesting areas, the main worry I have is that you can't know where to skimp on the resolution until after you've got the result.

I do think, however, that there should be some relationship between resolution and the "stickiness" of the surface (with higher friction variable, e.g. heavy rough). Given the higher friction areas, there will be less movement in rollout. Less movement in rollout means that the net effect of the contouring is less significant, which means that the resolution is less important, and we can probably save time in these areas.

I'll really have to think about this. It's a good idea.