An experienced live top guitarist like Michael Britt knows from practice how a profile behaves at rehearsal volume, through monitor wedges, in FOH systems, and in dense arrangements. That kind of real-world translation is difficult to recreate purely with headphones or theoretical EQ adjustments.
Yes, around 80–85 dB the Fletcher-Munson effect already becomes much flatter, so you do not necessarily need extreme stage volume to judge a sound accurately. However, live performance introduces many other factors beyond pure loudness curves (e.g. how does the tone that sit correctly in a loud band mix).
Of course I can always tweak profiles by myself, but professionally prepared live-oriented versions would save time, reduce guesswork, and provide a much more reliable starting point for players who mainly perform with bands.
Especially for users, like me, who cannot regularly test at higher volume levels at home, clearly labeled “Studio/Home” and “Live/Band Mix” profile variations could be extremely valuable IMO.
Perhaps then there would be fewer comments such as, "M Britt profiles sound quiet lifeless, and only come alive at band volume."