Ubiquitin, it is well known that Litvish gedolim have told people to eat in the succah on Shmini Atzeres.
It is also well known that many great Chassidish Rebbe’s who were talmidei chachomim didn’t, and to be dan l’kaf z’chus, even if we don’t understand it, we assume that they must have had halachic justification.
Nevertheless, that is an example where poskim have said to abandon a minhag because it can’t override halachah.
Sam, did you see the M”A I linked?