What type of anti-islanding does the Tigo EI Inverter use?

This question hit our service line shortly after the 2023 new year started as a result of a late-year addition to the PG&E Interconnection agreement. Pacific Gas & Electric is a California utility that services a large portion of the state. 

This is a highly technical question typically not found on any inverter spec sheet or external facing documentation, so the questions started flowing into Tigo Support. PG&E sent back interconnection paperwork that did not have this section filled in:

FYI: Tigo uses the Group 2A method. There is an application note on our website with an official statement regarding this anti-islanding method for inspectors or other permitting paperwork that may require this information.

Tigo Inverter (US) Method of Anti-Islanding