I'm interested in what you found with this. Glad you found something that works for you. I've had a gridboss/flexbox system with AC-Coupling (30 Enphase IQ7HS's) for about 2.5 months.
Initially, I was running off-grid for a time waiting for my utility approvals and the Smart Port for AC Coupling was active, powered the house and charged batteries from the surplus. Once batteries were full (since I have the IQ7's vs the IQ8's) the microinverters would fault out and systematically shutdown and restart, but nonetheless I had the option to use them without the grid present and could shut off 1 or 2 of the arrays on sunny days to keep the voltage / frequency low enough to keep part of the solar online.
Once going on grid with this setup and adding a generator... when the grid is down, my smart port is always off. The system only runs off full battery until the generator starts to recharge the batteries. I have not been able to figure out how to use my "Legacy" AC Coupled with the grid down however as soon as the grid is detected, the gridboss immediately turns on SP1 and the solar starts working again.
This is pretty minor for me because power is rarely down, but I'd still like to figure out what changed here, possibly the firmware on the gridboss or something that they did remotely that I have no control over. Both gridboss/flexboss had software updated remotely when I called for support to configure them for on-grid / sellback and things are certainly a little different now.
Jordan
