Although the microwave water heater is not a new idea, I cannot find anything on the market. I have spent a long time searching for one. There was another startup firm in UK and seem to be gone. Their setup was what WDRP called an inefficient approach in their patent filing.
Could you provide a website link to the specific product that say that? I look up both brands you mentioned, but they are just electric tankless water heater, which is obviously not a microwave type.