I think this arrangement is more interesting to look at than to see with. I have tried it with dual generator lights, and the arrangement can be a bit of a pain, especially if you want to turn on a secondary light while riding. I ended up moving my lights closer to the cockpit, on a modified bar outrigger for a computer. (Also, if you have cantilever brakes, there are considerations of interference with the lamp housing and the brake arms and straddle wires. If you have a front rack with braze-ons, you can buy hangers that let you place the lamp toward the forward edge of the rack underside, below the bag bottom and out of the way of the fork. This still doesn't get you around the switching inconvenience, but it looks good and works better than a fork mount, IMO.)

The idea of illuminating rough spots better by having the beam closer to the pavement does not result in enough benefit to outweigh the inconvenience of having the switches out of easy reach.