I would suggest some tests using different types of diffusion material on the front of the lights to help spread it out over the image, as it seems most of the light is being concentrated in the center, unless that is what you are wanting. Of course as the light spreads out it will become less intense, so finding the right balance will be key.
Some folks start with something as simple as frosted Scotch Tape, but there are all types of diffusion materials available. Lee Filters puts out a swatch book with color correction gels that also includes a nice selection of diffusion materials which are large enough to cut out and apply to at least 2 lights:
https://www.filmtools.com/leeswatchbook.html
You simply cut out a circle and attach it to the front glass using a tiny piece of double sided tape in the center.
You might also try using diffusion material on one light and keeping the other light clear. I also think bykfixer's suggestion of using some type of optic to place over the light, would be worth looking into, because it appears you are currently only using the center spot from the Fenix light (thus wasting the spill light), and the optic would concentrate the entire beam on the area you want to see, and choosing the correct optic would allow you to determine the size of the circle you want to see, and even have different optics for different flying heights.
Anyway, quite a fascinating project. I'll look forward to seeing what you come up with.