Multiple rigid body collision on custom brep

I am trying to drop a bunch of cubes onto a custom topography, such as I’ve set up in my script. I see in the Kangaroo examples there are examples of sphere collisions on custom breps and rigid body collisions on planes, but no rigid body collisions on custom breps, so I am having difficulty getting the rigid bodies to speak to both each other and the surface. Much thanks in advance for anyone that has any insight to correctly simulating this. multi rigid body solid point topography (1.1 MB)