Anything extra that emerges may sound as sweet as heaven but I am not interested in this kind of sugar-coating.
I too am not very interested in "sugar coating." You may recall my recent thread, "How do you judge your system's neutrality?" in which I was an outspoken advocate of the value of neutrality, where neutrality was understood as the absence of colorations, and colorations were understood as audible inaccuracies. So, in other words, I am not an advocate of inaccuracies, even when they are euphonic inaccuracies, or "sugar coating." We are in agreement about that.
With that in mind, the emergent musical characteristics I was referring to in the OP are not "anything extra" in any sense that impugns the accuracy of an audio system. They are emergent, simply because they are (1) different in kind from the components' characteristics; (2) caused by the components' characteristics; and (3) difficult to predict from the components' characteristics.
Perhaps it appears that I am suggesting that emergent musical characteristics are "something extra" because I pointed out that they are DIFFERENT IN KIND from the component characteristics from which they emerge. But that is not because "something extra" has been added to the musical information. It is simply because they are the product of TRANSDUCTION, the conversion of one type of energy to another. That is quite an uncontroversial thing to say, and something of which I am sure you are aware. So I suspect we are in agreement here as well.