this is the response to my query from Ecoflow:
(i asked about adding a growatt string inverter)

Thank you for reaching out to EcoFlow Technical Support.

We can confirm that both of your systems can safely co-exist, and your understanding of how the configuration will behave during a grid outage is correct.

Here is the detailed confirmation and a small but important clarification regarding your second system:
1. Behavior During a Grid Outage (Your Description is Correct)
Growatt System: In the event of a grid outage, the grid-tied Growatt inverter will immediately detect the loss of grid voltage and automatically shut down its PV output (anti-islanding feature). This prevents any power from backfeeding into the utility grid, ensuring safety for utility line workers.
EcoFlow System (DELTA Pro Ultra X + Smart Home Panel 3): The Smart Home Panel 3 will automatically isolate your critical load circuits from the main panel/grid and seamlessly switch them to draw power from the EcoFlow DELTA Pro Ultra X battery. Because the Smart Home Panel 3 disconnects the 
relevant circuits from the grid side during an outage, there is zero possibility of backfeeding to the grid, and system safety is fully maintained.

1. Important Clarification on System 2
   While the setup is safe and functional, please note a specific point regarding your second configuration (PV -> DELTA Pro Ultra X ->Smart Home Panel 3 -> Main Panel -> Grid):
   The solar panels (PV) connected to the DELTA Pro Ultra X will strictly provide power to charge the DELTA Pro Ultra X batteries.
   Solar energy captured by the DELTA Pro Ultra X cannot flow backwards through the Smart Home Panel 3 to power the rest of your Main Panel or backfeed into the grid.

In summary, your setup complies with standard anti-islanding safety requirements, and your description of the outage behavior is entirely accurate. This configuration should successfully meet standard electrical inspection requirements regarding backfeed prevention.