Sorry if this is a wrong community to ask these question since my system is only partially DIY, but does anyone have experience with EPS systems like EcoFlow Delta?

I’m trying to figure out exactly how it works when all 3 sources of power are available: battery, AC and solar. Is it able to use them in combination if solar doesn’t provide 100% of demand?

And if anyone is using UPS units, how are you dealing with lack of ground? I’m thinking of daisy chaining UPS to EPS to avoid sensitive equipment from shutting down during failover, but I’m concerned that UPS will not like operating without ground.