Can anyone point to resources, reviews or experiences on monitoring power usage in 240v ac (US)?

Looking at the new energy dashboard features …. I have opower integration of my electricity usage and a nice graph. However most of my power usage is from a heat pump, and EV charger, and maybe a garage heater. All are 240v, larger current loads. So the new feature is something about graphing device usage with overall usage. So that would be cool to add

I started searching online and it doesn’t seem especially positive. I see a few clamp meters with integrations but also see reviews that they’re not very accurate.