The API reference page on BillboardGui for StudsOffset(WorldSpace) and ExtentsOffset(WorldSpace) is very vague and unclear, even up to reusing the same wording to further obscure the difference between these properties. SizeOffset is also contributing to this. There are five offset properties and the difference is massively unclear other than making best case assumptions on their use.
It would be very helpful to explain the difference between these two, or show how their differences may highlight in gameplay. Knowing which one is best to use for certain scenarios would improve the UI development experience greatly.