Is said the Low, End of the QR mount .. light has a shadow contrast,
holes in the road stand out.

I have a lowrider hoop mount on my touring bike, [Paul's Gino for LED battery light]
26" high

Dynamo powered, a fork crown mount on the 26" wheel, [nylon-plastic]
33" off the ground

a mount in the headset stack of my Bike Friday, It's a bit of a kludge,
Bike Friday folding steerer mast is a 1" quill , so the Nylon piece
made for threaded 1" headsets, I got from Peter White,
got inserted over the quill , then I put the quill back in the fork..
It's light, 30" off the ground..