Rock hard license plate relocate bracket & light bar
 

Has anyone tried to mount a single row light bar to a spare tire license plate relocation?
For reverse light since the stock are too low power

It wouldn't be hard. All you would need to do is put the supplied L brackets on it by either bolting or (if I were to do it) welding them on.
I've had a small 7" single row on my bumper for over a year now that I paid $12 for on Amazon. It weighs next to nothing and actually has a lot of like output. It would probably work well for your plan.

Not sure if you already have the license plate relocated or if you are just brainstorming on how/where to mount. If you have the stock carrier you can mount one to aim through the spokes of your spare. It's not the best method but it's free and gives better peripheral light than you would think.