You ask some good questions. At the risk of burdening you with knowledge 
, here are a few answers:
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Sense prefers smartplugs that deliver energy info for two reasons: 1) energy results fit naturally into the Sense energy focused UI and fills the gap for many devices that are likely near-impossible to detect today, plus 2) “ground truth” is best served up as energy/power measurements, not on-off:
2019 Data Science Update - Sense Blog -
Sense has one hub integration today, the Philips Hue lighting hub. The Hue is a bit unusual in that it has embedded, calibrated power calculations for each exact model of lightbulb as a function of on/off/dimmer level. Not sure that is possible with all home automation system or all forms of automated devices, but it might be a good example of how other hubs could be integrated. Two important features - 1) It computes energy/power for on/off/dimmed devices, plus 2) it communicates with Sense via the local Ethernet subnet.