Arbor Arms just introduced the Ambush Belt and it has a very clever trick. It is fully MOLLE compatible… while also being thin enough (.2″) to pass through the belt hardware of a duty holster!
From Arbor Arms:
The AMBUSH BELT™ is a minimalist MOLLE belt that is very lightweight, extremely low-profile but still stiff enough to support a fighting load. The AMBUSH BELT™ was designed for users that require the lowest profile system possible but still desire the stiffness and stability of a layered belt system. The AMBUSH BELT™ is the thinnest MOLLE belt on the market at just under .200 inches thick, and at the incredibly low weight of 6.2 oz*. The AMBUSH BELT™ also features our Double Reduction Cinch System that allows the belt to be tightened easily while worn for perfect stability and comfort. The AMBUSH BELT™ features our innovative “Half MOLLE” design that allows additional modularity and customization of the belt configuration while still remaining extremely durable thanks to its Laser cut laminated construction.