So what you are saying is, when you have a 3kW system they expect something like (example) 40 Units that they have to pay for at the end of the month, but when you then install 6kW system beside it and you feed in 90 units (again example) that they could come and visit?
I like the idea, but after the @Thaifish story I am (personally) staying far away from Official Net Metering.
For us it's either
A- Being "Illegal" and Exporting
B- If a NON Export Meter is installed, a system with ESS and a fallback to the grid only in case our ESS runs "dry"