It would be nice to have certain objects persist in Fog of War zones, but to have others ReHide. This would allow, for example, modular walls revealed in a DnD-style map to persist, while monsters would ReHide if the Revealer didn't maintain Line of Sight. I think having an Object Toggle to either force an object to ReHide, or to ignore the ReHide option of a Fog of War zone would be a very intuitive way to accomplish this.