LED lights can put a lot of harmonics onto the system.
So there is a factual reason why it may be better.
Maybe the displays do a similar thing?
Bluesound Vault 2 Lights Off
Owned my Vault for probably a few years now and never went into the settings far enough to see the light on the front on top can be dimmed or turned off. On the rest of my gear I turn the displays off and feel it makes a difference but splitting hairs or fooling myself maybe. Of all my components turning the lights off, the Bluesound is noticeably better with the lights off. Difference is more open with the top end being a little more extended and not rolled off. Running into a separate DAC so not sure if the difference is there when using as a standalone player. I have not read others mentioning this, and betting others have not experimented either. Definitely worth a try.