Didn't misunderstand... But it's all opinion and preference. First, white fog lights are pretty much worthless IMO. Most manufacturers do fog lights at all for style, not function. I hope BMW did the height for functionality and not style but since they're white I'm already questioning function. But anyway...
In my experience, fog lights under about 18" off the ground typically will focus most of their lumens 2'-10' in front of the car and are wasted as the driver can't see that close due to the hood or it's not useful at more than 5mph and in if it's that bad you shouldn't be driving. Due to DOT requirements of downward lighting angle and avoiding fog lights causing problems for oncomnig traffic you can only illuminate further down the road by increasing the height of the light. My preference for fog lights are most lumens focused about 20'-40' ahead, still allowing you to see at 1mph in the worst of fog to get off the road but in mild fog at 20mph.