I dont know if its a unique issue with my RS2 but whenever I pan fast in briefcase mode the gimble wants to flip one axis on its head, turning the camera upside down violently.
It seems like it tries to overcompensate the movement. It is perfectly balanced. The Ronin S did not act like that.

Yeah, mine does the same. Shattered a filter last time, haven't used the gimbal since as DJI aren't able to give an answer on what is causing it.

Posted about my issue here https://forum.dji.com/forum.php?mod=viewthread&tid=232157