I have been looking for something like this and am excited about the project. I watched your installation video but my US panel does not have the same configuration with EU panels. I only have limited experience working with EU panels when a make trips to Greece to visit family but they have 3-phase and here in the US I have 2 single phases.
I have two service mains that feed my main panel (over 60 circuits in the house) for a 200 amp service main. Each main has ~120V coming in. The main service disconnect in that panel doesn’t have lines out, instead it feeds into the panel bus bar directly. It is not possible to directly connect to the bus bar safely or otherwise without first using a breaker.
What I can do is connect the meter to an existing 2 pole breaker I have that powers another power meter.
Anyway, Looking forward to finding out if the meter will work in my main panel.