We now have some additional information on how the new patent pending Grid System from Snake Eater Tactical works. They debuted this system on their SET Plate Carrier and it has generated significant interest since then. The video below shows how the Grid holes are used in conjunction with a paracord and a cord lock to mount pouches.
Additionally, the image below shows how the system be used to stack pouches that are otherwise not made to be stackable. Shock cord is used in this image to allow for the expansion of the Rifle Mag Burro pouches.
You can check out the Rifle Plate Carrier at Snake Eater Tactical.