Here is my current process to freeze and pulverize material:
A 8L stainless pot sits on a 10lb square block of dry ice in a thick wall cooler. Flower and/or trim is added and pot is filled 90%. A ~1lb chuck of dry ice is put into an open top aluminum foil "boat", and this is set on top of the flower/trim. Lid covers the cooler and material begins to chill. After ~20 minutes, I remove dry ice boat and with a large stainless pestle, I smash the material down into the pot. I repeat this process over the next hour until material is ground to fine consistency. The colder the material the easier it is to pulverize. The material in pot is reduced in volume by 60-70%, and I will add more fresh (unsmashed) material and repeat process until pulverized material fills the pot to 80%.
I know that you are looking for a larger and less labor intensive process, but you could scale this a bit and test before spending $,$$$ or $$,$$$.