Question about Region3 voxel grid

So, the voxel size is 4x4x4. I have a game where it places blocks that are the size of 4x4x4. My question is, should their positions be 0, 4, 8, 12… or should it be 2, 6, 10, 14…?

You can test it by seeing what ExpandToGrid returns: Region3 | Documentation - Roblox Creator Hub