2 inverters "work" but the software isn't ready for dual inverter setups.
Example: Inverter 2 doesn't know what inverter 1 can power the house from solar, so that cheap power you purched at night is being used by inverter 2, while you're dumping the excess solar to grid from inverter 1.
You can charge both at night and you can discharge off peak. I have limited my power to as little as 5p average with 16.6kw to use in peak (+7 kWh hot water generation by heatpump, plus car)
I limit my non solar inverter output for continuous load (400w) and let the other handle peak.
Multi inverter logic is expected this year.
You can chain batteries to one inverter, the problem is charging them in your cheap window.