i would be cautious against eqing high frequencies based on reflections and sound power, when direct sound is fine. The ear works as a directional filter, and reacts to sound coming from diffrent directions diffrently especially at high frequencies.
Therefore, you may be messing with the...
"Gently rolled in above 10 kHz, the ribbon reaches full contribution from 14 kHz to well beyond 30 kHz, far above the audible range."
From Dali option whitepaper - https://www.dali-speakers.com/media/1669/opticon-whitepaper.pdf
Looks like more of a marketing decision to me.
Probably corner loading and loads or room gain from an untreated room. A "well placed" mode can boost bass by more than 15db.
Also, if the music or the content he listens to only goes down to 30hz, that may also be a reason as the port does produce output at 30hz.