But it's not
purely cosmetic even so, because alignment changes
can affect content. For example, some romances have alignment requirements or restrictions. As do other dialogues offered to you in the game (and in mods I reckon). On a lower level, many items have alignment restrictions. I assume Bookwyrme had a reason like that for making these, as (according to her) there is only one pair of "cosmetic only" shoes in the mod, and it's not these. They are otherwise equivalent to the Helm of Opposite Alignment, only not cursed, meaning you can equip and unequip them as you please, to switch or restore your alignment accordingly. But yes, they are shoes of alignment-changing, not shoes of personality-changing, so it's not like the character will start spouting new lines. Let's face it, that's fairly realistic (not to mention globally changing all
NPC dialogue based on alignment would not be feasible to put it lightly). There are plenty of good people in the world that may seem dour or moody and plenty of evil folks who will be quite happy and kind to you (until they slit your throat or whatever).