No Local/World space option for Terrain/Set height?

https://docs.unity3d.com/Manual/terrain-SetHeight.html
Here in this wiki entry, it says the Set height tool is supposed to be able to switch between Local/World space.




However, I can't find this field anywhere in the Editor while using it:




I've updated Terrain Tools to the latest (preview) version currently available (2.0.2)
My Unity is slightly outdated, though (using 2019.2.19)

What could be the problem?

Thing is, I wanna be able to Set Height to 0 where zero is BELOW world Y=0. But whenever I do that (no matter the terrain object's own Y coordinate), painting with Set height = 0 always sets the height somewhat above Y=0. I thought switching to local space might help. But can't find it.

 

2019.2 docs don't have this as an option https://docs.unity3d.com/2019.2/Documentation/Manual/terrain-SetHeight.html
2019.3 has https://docs.unity3d.com/2019.2/Documentation/Manual/terrain-SetHeight.html

I am currently on 2019.3.0f6 with Terrain Tools 3.0.1. This option does exist on my version.