If this argument was as solid as you say, then all routine checks would be pointless.
I don't know about traditional blood testing, but a permanent implant which checks HR, pressure, glucose, temperature & oxidation would be pretty useful, not necessarily to diagnose anything, but to provide data for doctor when patient has actual symptomps.
What makes us conscious anyway? As I write this sentence, my brain generates words and contracts specific muscles in my hands to type, but I don't really understand how. I'm just aware that it happens. Apparently I'm no aware of every single neuronal activity, so what I am aware of?
Yeah, it's not immediately obvious, but if we created perfect utopia where conditions are ideal, perfectly matched for given individual, heritability would be 0%.