If anyone is at all interested, the vertex position information provided in the info panel is in a coordinate space relative to the current zoom of the currently active composition viewport, not the coordinate space of the composition.
So if your composition is 512x512 pix and you're at 200% zoom in the comp viewer you're going to see coordinates within this space of your vertex position in terms of a 1024x1024 space. Similarly, at 400% zoom you're now in a coordinate space of 2048x2048 for the vertices of your path objects, but NOT for the info panels reporting of your current mouse positioning.
You will therefore not have true pixel precision available to you for vertex movement unless you divide whatever coordinates you see by the rate of zoom, or work at 100% zoom.
Is this in the documentation anywhere?
Is this a feature, or a remnant of a finer nudge feature?
Anyway to turn on pixel snapping for a zoomed in view when moving vertices of a path, shape or mask?
It works as it always has/ is designed. Same answer as your otehr post: If you need precision, use Illustrator.
Go back and re-read. The other question wasn't answered, at all. It was, in fact, the source of the misleading information about vertices coordinate space.