I've used the Vollmer cut stone sheet around a Styrofoam base for a homemade passenger platform. I like it. Over time the glue I used let me down but that's an easy fix on an accessible platform.
Cutting individual blocks out of foam takes more patience than I have. QG 48's Styrofoam workmanship is excellent and works well at a distance but the material doesn't hold up to close ups like the 5th picture. B who's ever getting that close to it anyway?