One thing we can be certain of. Perfection is specific to the individual, the time, and the circumstance. What works for me today may not work for you even in identical circumstances.
And yet, there is a perfection we can both achieve as long as we recognize what’s perfect in one instance will never be the same as the second instance.
Take for example loudness for a particular track. Much depends on the room, the track itself, the number of people in the room, the speakers, the cabling, the mood, the time of day—even the room lighting.
What we can agree upon is that every track has a perfect listening level specific to that moment in time. What I think is often confusing about this observation is that it is never the same for two systems or two people. Thus, me telling you that the perfect listening level on Flying Blind from Temporary Circumstances is X on the BHK isn’t going to do you a lot of good when it comes to duplicating what I want you to hear.
That is, of course, because everything for me is different than for you.
What we can suggest with some confidence is that getting the volume correct is critical. And you will know it when singers Jessica and Giselle are in the room with you.
More than that we cannot say.