On occasion I'll take the "bike path" to/from work. This has 3/4 mile of really nasty pavement, such that I think of Lance Armstrong's "cross country" downhill leg from 20 years ago while riding it some evenings.
Anyhow, the fork crown mount seems to be a pretty good balance between lighting up the path and highlighting the ridges from the cracked pavement. I've thought about moving it to a Nob on the rack mount in the middle of the fork, but I doubt I'd want to go all the way down to the bottom of the fork. At some point it would be so low that surface irregularities could hide from the lowest light mount -- things like puddles if it's raining, or broken glass.