The addition of the white LEDs on the side is an excellent idea! I was surprised at how much if. Difference that made. This will definitely be part of my next trailer retiring project as well as on my list of upgrades to any functioning set of trailer lights. It is quite often that I find myself backing trailers in dark places where extra light would help! Thanks for that tip as well as the info on the rarely used five flat style wiring.
Looks like I'm a little late to your project, but if you find those side mounted reverse lights distracting or hindering you can go to any contractor that installs aluminum fascia, flashing or eaves trough, grab a couple of small scraps (preferably white on one side), and form the scraps into shields to direct the flow of light while keeping it out of the operator's eyes. Other than that, I love the addition of the extra lights.
My experience with LED lights has been disaster they just dont seem to last long, I bought a light strip for my Ram and in less then a yr almost all the lights were dead and the truck sits more then driven