Post Purim Melavah Malkah?

My grandmother said that her father who followed Oberlander minhagim had the custom of always having a fleishig Melavah Malkah the Motzai Shabbos after Purim. Unless Purim was on a Saturday night/Sunday.
Has anyone ever heard of such a custom? I am trying to find out if this was a regionally based custom or merely a family custom.