A big PS lightly loaded will hold up longer because it has bigger capacitors however under heavier load that changes.
Under 10ms is considered to be the target for a good UPS.
They dont have a fast enough switch over time to replace a UPS.
However you can plug a USP into one for extended run time if the output is good enough not to trigger the UPS all the time.
I know people who do it with ecoflow units combined with...
Power in my area is stable but I have a wife that doesn’t understand circuits and power budget. She routinely plugs her hair tools into the master bedroom outlets instead of the bathroom because the bathroom gets “too hot” our equipment closet is...