This is excellent information. I was trying to power (2) single phased paralleled inverter and they kept freaking out. I could not figure out why. I will give this a try next time I open up the main breaker panel.If you are feeding input off each phase in the main panel, then you are inputting 240V split phase.
If you want 120V single phase, then it has to all come from 1 phase, you can use one 25A breaker to one inverter, skip one space in the main panel and another 25A breaker in the next spot to the other inverter.
If you are inputting off 2 separate phases, you will have glitches.