If you're familiar with Unity Tactical's Fusion which is a modular mounting solution design which is also lightweight and can allow you different configurations for mounting your weapons accessories have posted at their Facebook Page their Fusion ARC Rail Hub which is basicsally their Fusion modified to give the same mounting solution on the ARC Rail Adapter which is seen in the OPS-CORE line of helmets.

If you want to mount more items on your helmet, provided you have the rail adapter, then this solution can greatly help.