Tesla:
Thanks for the California 'way'. It's a little different here on the east side.
That's the NorCal way, SoCal is quite a bit different, but the AHJ does NOT have any say on whether you use a 5-pack or a separate house/meter panel.
Either way would work, but the POCO makes the final decision on what's acceptable and PG&E does have a design guide for this issue.
I have never heard the acronym EUSERC used within SCE or SDG&E territory.