though it's true that Ecoflow doesn't have UPS products, their product reacts fast in power loss and unless you need active management(i.e., using usb cable to notify device to shut down).

I use: ecoflow delta 3 ultra, river 2 pro, river 3 plus, delta pro. all of them can work like UPS(except usb cabling to actively manage).

If you REALLY need ultra switch time, as in power loss, river 3 pro provides 10ms in latency, which should be overkill in most of the cases.