Only thing about that is that if the mount comes loose and the unit contacts the wheel, the wheel direction tends to drive the dynamo in the fork direction with possibly bad consequences, like jamming the wheel, etc. Out front seems a little safer. I dunno, though, might be more of a hypothetical concern than a real one. I'm pretty diligent about getting everything tightened up and lock/star washered well and very rarely have stuff work loose. Bracket mounts on something like that might be one of the cases for loctite on a bike.

Otherwise, though, that would be a clean solution.