Lezyne's lights use a typical rubber ladder-strap mount. The way they're set up is that they have an adapter block for round bars that slips over the ladder strap, but if you take that off, it's got a flatter surface for fitting on top of aero-section bars.

I like the idea of a light that uses a gopro mount, but in most cases, this would invert the light, and if the beam is shaped at all, that's counterproductive.