Answering back to front: no, I haven’t, and I’m not sure. I don’t have a problem with it as a perversion, but I’ve never been involved with someone who could handle it, so it hasn’t been an active part of my fantasy life.
As with raceplay, I can see how fat-shaming is a useful means of accessing some really primal insecurities and playing with them, but I don’t write about it much because I don’t want to be clumsy about pushing buttons I don’t fully understand.