Use-Cases for Vector2int16, Vector3int16, and Region3int16?

What are the uses for these? I could not find any. All API functions I know about use regular Vector2/Vector3/Region3, not the int16 versions. When would I actually use the int16 versions?

Terrain used to use them. This was a really bad idea for non-obvious computer science reasons so they stopped using them.

Why are they still around then?

Like any deprecated functions, they exist so games that still use them don’t break.

How were they used back when the could be?

More info in this post:

They aren’t used very much