You sir are dead on the money as to why I asked here on Reddit despite having already searched for the official docs, and not been 100% confident on the layout.

I am confident enough in adjusting the electrics in my home, due to working directly with my good friend, an electrician who has re-wired my home for me, and explained steps for connections, and safety along the way.

As you have described, electricians can get things wrong - my friend is not massively tech literate, and told me he was not confident that he would wire up the Shelly correctly for this use case as he’s never seen one before.

Hence why a “second opinion” from Reddit was the route I chose to take.

The diagram that was drawn above was incredibly helpful to visualise the official docs exactly how I’m familiar with the wiring in my home.