Never heard of it but here are a few other Challah minhogim.
On Rosh Hashana the challah may be rolled into a circular shape (sometimes referred to as a “Turban Challah”), symbolizing the cycle of the year. Sometimes the top is brushed with honey in honor of the “sweet new year.”
The Middle Eastern Mizrahis use a flat bread resembling pitta. In some traditions twelve pitta breads are used, to represent the Lechem Hamishneh. They are arranged in two layers, with the central two breads of the upper layer used for the blessing. Mizrahis of Central Asian-Bukharian descent eat a bread called leeposhka.
For the Shabbat after Passover, some families have a tradition of baking “shlissel challah,” with the impression of key on top or an actual key baked inside. This is supposed to be a segula for one’s livelihood.