I like this because its very low profile on the inside.
It is in stock with 4 and 5 conductors.
Could a generic mount that just presents a small flat surface to Dual Grip to be fashioned then? We can all figure out how to clamp something to our bars. Something like this perhaps (not to scale).
I forgot to post this yesterday I think. This is the back plate with the electronics. Those screw holes are for hooking some kind of rubber band or fine cable to hold the electronics fast.