Adding additional panels to existing system, how to figure?

[Ampster]

Inverter size is a non issue as I used micros.

Micro inverter size is still an issue when applying for a Net Metering agreement. AC capacity is what the utilities are concerned about when evaluating the impact on local transformers and substations.

[MGE]

They didn't bat an eye when I told them I was using the older Enphase M215's.
They also didn't care about the (4) 260w panels I wanted to add since they would be clipped at 215w by the micros.
Install is all done and checked off and been running for a week or so.
First real sunny day we have had since I added the panels.