BTW, in my GM_Volt.csv (that came with EngineLink), I have:
In your Bolt CSV, that's marked as an unknown, but as I recall, this has provided meaningful-looking voltage measurements, and this is how Inst Kpower is calculated for the Volt and seemed to work fine for my Bolt, specifically it's
,Inst. kPower,-100,100,kW,[HV Volts]*[HV Discharge Amps]/1000,0
Is there some reason you're not using this one?