mechanochemical processing technology patented by ANO

To the experts of ANO
There are several remarks on how ANO has patented the MCP technology that gives them an edge over the competitors in manufacturing nano particles. I've been trying to do some search on this patent as well as any other patents that ANO may have. From a quick google patent search, it seems that patents related to manufacturing of ultrafine particles as well as some other patents granted to ANO and/or University of western Australia has expired, except a patent related to "Process for the production of ultrafine plate-like alumina particles".

If the patents related to manufacturing of Zinclear has indeed expired, what stops the competitors to setup similar similar nanoparticle production processes. I understand that it may not be as easy or straight forward, and may require product approval from clients/FDA etc., but just trying to understand if MCP technology is indeed a moat.

Please correct me if I'm wrong regarding the patents or its expiry.