Yeah it seems like the inverter manufacturers don't see demand for that. I was thinking maybe the Victron Multiplus-II 2x120 could be paired for 240V output but I was wrong, that's only on grid power, it won't make 240V from battery.

Obviously the inverters and pairing technology exist, but I don't know where to buy one retail.

The Bluetti Apex 300 is an expandable 2.7kWh 3.8kW dual-leg battery + inverter + solar generator for ~$1000 (on sale).

The EG4 12kPV does 8kw split phase output and is $3k, but haven't seen anything smaller than that yet.