So how do I get/change/remove/reduce crests, anyway? The roadmap doesn't suggest that there's a missing building that would deal with it, and some of them can really force your characters into a particular role that doesn't suit them (like the one that increases healing in the back rows and increases the damage you take in the front rows). It definitely feels like something that shouldn't randomly show up and progress at some point after you've already started developing your character, only to be locked in for the rest of the game.
I also found another bug which can actually be useful. If you're wearing a cursed accessory that is either infinite or could become infinite when unequipped, you can hit the button where the X would usually be to unequip it, even though said X is invisible. This doesn't work for non-accessories, though. It also results in some weirdness if you have enough copies to go infinite. You'll end up with four in your inventory, and then have to equip/unequip a non-cursed one to properly merge them.