Thought I’d share my findings as I managed to un-parent some game objects with the hope that they won’t light up.
In the screenshots, only one component is highlighted, via gaze input.
The moment I touch it with any finger, all components from the pump light up, despite the disassembled components NOT being under the same parent, but simply in hierarchy with no parent.
It is unclear to me why it behaves as expected via gaze input, but not touch 
Also, since they are no longer parented, why do they still light up? Does VisionOsHoverEffect fetch children on awake/start, then never updates?