If I had a Gen3 I'd just cut the RH footpeg off, file it smooth and paint the muffler hanger black. Grind out the honeycomb reinforcement in the back of the stock muffler hanger to lighten it if it will not be used to hand a heavy stock muffler. I don't think you will get anything a lot lighter than that unless someone makes a carbon fiber muffler hanger. If you want to plug the fairing hole on one or both sides, there's an artists clay called Sculpy. I'd recommend the firmest compound they offer for this sort of project. You could use Sculpy to form a piece that will fit inside the hole in the fairings. Fashion a lip around the circumference to adhere to the inside of the fairing. Bake it in the oven to harden it, sand it, paint it and glue it in with silicone. If you need some kind of hole for a bracket to protrude from, you'd just shape the Sculpy as needed before baking. I was planning to do something like this for my Gen2 someday.
