I have the above meter running 3 phase and about to run solar single phase for most of the house circuits.

Can someone tell me if the meter aggregates the 3 phases or bills each phase separately?

So for example if I have each phase supplying 2kW but am generating 6kW, do I get billed for 0kW or do I get billed for 4kW, and credited for 4kW for the export?

Reason for the question is do I need to move daytime power usage over to the Solar supplied phase?