Still annoying and expensive though. Biochar blocks emf waves apparently so that might helpful as a component in plaster.

Also I find it curious how the media and gov are crowing all the time about boogie men hacker teams in Russia and North Korea attacking things like NHS computers but have now decided to get us all to have a highly hackable switch in everyones house!

I am sure there will be other people more clever than me that can hack these things and highlight the security issues and just how stupid the whole idea is. Definitely a good idea to hold out as long in my opinion perhaps you have 'COVID' or whatever the latest disease is when they come round to force install it! Put a box round the current meter etc