Generally units that have CEC-HDMI control, or whatever its called, will have an option in their menu system like "accept turn off/on commands via HDMI-CEC, yes or no?" and I don't recall ever seeing that in my 3500STBii ch3/4 menu system so I assume none of the other related family units have it either.
In A/V reproduction accuracy, there IS no concept of "accounting for personal taste/preference". As art consumers we don't "pick" the level of bass, nor the tint/brightness of a scene's sky, any more than we pick the ending of a novel or Mona Lisa's type of smile. "High fidelity" means "high truthfulness", faithful to the original artist's intent: an unmodified, neutral, accurate copy of the original master, ideally being exact and with no discernable alterations, aka "transparency".