4. SSR Amon got buffed, I haven't hunted the date for it yet. But it is fairly recent, so not something we'll get on Nutaku for ages.
I think it was changed on 19th march. At least the change to the def debuff to hit all enemies happened then along with other changes. So I'd assume it got changed to C frame with it, havent seen any other changes to her going through the patch notes