Recently I've played through with a character that started as a wyld elf, and the moment Ice Roses were available, used them to transform to a boreal elf. All of the traits that would differentiate between the two elf types, like the skin color, hair color, and loss of the visible wyld mark stuff all happened, but the appearance screen still calls my Champ a Wyld Elf, and I don't get why she isn't being considered a boreal elf now.