A nest thermostat using plugin v2.0.53 has some states that I'm not sure of...
setpointCool / setpointHeat - These two seem to be correctly tracking the high/low points that I have set on the thermostat
target_temperature_low_f / target_temperature_high_f - These two also seem to be tracking what I set (with the "high" matching the "Cool" , and "low" matching "heat" as I'd expect)
But then target_temperature_f ... it is actually a degree lower than the low/heat point, so I'm not sure what it is trying to tell me. (i.e. I have my nest currently set to stay in the 69-72 range, but target_temperature_f is responding 68....)