Thanks to node "Set Global Time Dilation", I saw that I was not rotating each object correctly at birth. I was passing each one the rotation info of a general object, which of course has a pivot in a different place.
@maxim Reading that toot completely out of context, my first thought was "Wait, unreal even simulates general relativity now?"
@grizeldi I catch glitches while reading others, because writing about gamedev always causes something in my brain to arise.