That sure looks good and is a very clean installation.
I don't know if it's really a suggestion or not, but what I like to use for snugging wires up is leather. I make my own thongs (thinnish leather strips) out of scrap leather. If you cut a scrap that is say six inches in diameter (doesn't have to be a circle, just not something with sharp corners, and starting at the outer edge with scissors cut a strip say 1/4' wide and just keep going around until you get to the center. It's amazing how much continual thong you end up with. I use scraps of black elk hide mostly and instead of a tight knot I leave the ends with maybe an inch hanging. To my eye it looks good. On the other hand I used to do a lot of leather work making bridles and such for my Indian ponies and like leather a lot. It also tends to blend in with the seat upholstered in the same leather and foam grips covered and hand stitched in the same elk hide. I usually do the grips with a bit of fringe hanging and the ties for wiring with a bit left hanging kind of repeats that fringed look. It's all a personal thing, what appeals to a person. For me the leather is a kind of signature, like your coin hidden somewhere on a bike. You do it because it satisfies something in you. Who can explain it? Doesn't need explanation maybe, eh? I love your trike.
SB