Can understand your frustration. I’ve been trying to post a better set of expectations around on this forum, based on experience and knowledge about how Sense works.
We might see a broader range of supported devices as Sense rolls out progressive detection, but their initial scheme that relied on immediate detection of on/off clearly wasn’t going to fly for most electronics, variable speed motors (electronics) and inverter appliances (electronics).
I would differ with you on two points. All of my Kasa smart plugs maintain their on/off status when they are powered up again, so you might have had a bum unit. And they do measure power accurately with 1W resolution, so I’m not sure what level of accuracy you were looking for on your high-efficiency power supply. I monitor AppleTVs that have 1-3W of standby power usage very consistently. I can’t see why you would want to monitor power usage less than that in the household scheme of things unless you had hundreds of such devices, in which case I would gang them all onto a single Kasa device.