Apologies for re-opening this old thread, but as an industry insider, I do know how this works. I hope this helps someone, as I came across it whilst looking for something similar.
1) Yes, it is possible for 1 "import" meter to have 2 MPANs. This occurs when the site has (or had) separate heating and power/lighting circuits from the meter. In most properties the power goes from the meter to a fusebox, and at that point the separate circuits for power, lighting, cooker, showers etc are connected. However, if a heating circuit comes directly off the meter, and consumption is recorded on its