Show me a consumer UPS that is >$500 and actively conditions voltage within the 110-125v range.

They don't do it, if your UPS was actually actively conditioning power due to common voltage fluctuation it would need a fan blowing to cool off the components.

Consumer UPS are a crude failover in the event of an actual electrical event, whether it's an outage, a power surge, or an actual brown out(<100v). They use a trip switch and only kick in milliseconds after an actual power event. When they do kick in they provide a nasty square wave output.

You see where you're mistaken, where they bullshitted you, is regarding low voltage events, if there is an actual brown out, which are pretty uncommon, and you're getting say 95v, then they will trip into the on position, but even then they can't sustain that voltage correction over long periods because it's still draining the battery.

What model do you have? Let's have a look at the specs, what's it's active mode output voltage variance? Do you really have a consumer UPS that does active voltage conditioning all the time? I'd be curious to know which one.

You know a simulated sine is still crap compared to a true sine right? Any simulated sine output mode is definitely lower quality than the grid.

Certain houses and areas are more stable than others but all fluctuate +/-3 volts on a second to second basis with large or smaller spikes due to weather, transmission, power plants, etc.

This is the original section of your comment that I was responding to, no consumer UPS is actively conditioning +/-3v fluctuation, the power supply in every electronic device is already perfectly capable of running on at least +/-5v between 110-120v without a problem.