We have an unique and quite elegant solution for this. Two MP-clamps (we call it Multi-Purpose clamp, shipped with a shackle) and a lanyard with two snaphooks, which can be attached to any housing with two strobe mounting balls. All standard products from our Light Mounting System. We have been carrying rigs as heavy as 10 Kgs with this configuration.
These MP-clamps can hold a strobe mounting ball or YS-style stem instead of the accompanied shackle, for adding more lights to your system.