Following this logic, which I agree with, wouldn’t blind testing, or any A/B testing be compromised because our brains are always in analytical mode and therefore feeding us inaccurate data?
The data is the signal. The brain is what does the analysing of this signal, not the feeding.
Some form of blindfolding is necessary by definition, and a near instantaneous switching mechanism needs to be used. In a perfect test environment you wouldn’t be aware of when it has been switched back and forth.
Together with dB level matching - that might sometimes be the tricky bit (that’s an understatement), and the nuances that have been noted may well be because this step isn’t followed correctly.
That’s a good start.