With a transfer switch that does not switch neutral, the system ends up with neutral-in tied to neutral out on the inverter. There are a few big questions that need to be addressed in this case.
1) Does it work? As best as I can tell, it seems to work with many (most?) inverters.
2) How is N-G bonding handled? For the older version of the GW 3K, there is no internal bonding so this works well. For the newer version of the GW 3K or any other inverter that has dynamic bonding, the bonding must be disabled.
3) Is it supported? This is far less clear. For the older versions of the Growatt 3K, they said it is supported. I have not heard a definitive statement from Growatt, MPP or EG4 on any of the units that do internal bonding.