I am chasing up a guy locally who makes junction studs which are simply a bit of insulated thermo plastic with a central stud which can be 1/2, 5/16, 3/8 or 1/4. It just has two mounting studs either side of the central stud. Very small and neat but does not have the little cable organiser things that the MAD ones do.
I also had a look at the local hardware store and found something that make work. I will try and find a pic but it is simply a triangular piece of plastic with a central stud and you can chose 1/4, 5/16, 3/8 and 1/2 sizes. Very small and neat and will do exactly the same thing. $3 each aswell.