Fracturing with 2 depths and modeled chunks?

I want to fracture my stone wall into it’s stone pieces and then make it that these stones can also fracture.

Now I know I can use “import fbx chunks” to get it fracture into my stone pieces but to fracture those stone pieces in depth 2 I need to use PhysxLab but the problem is PhysxLab has no “import chunks” feature.

I tried using other features of PhysxLab instead of using my modeled stone pieces but it was all not working out. I could import the base mesh as stone pieces but that adds lots of polys to the wall that would only be needed when it gets destructed.

Any ideas?