Bug Terrain Toolbox - Cannot Delete Splat Map

Hey!

I am currently looking into memory consumption of our game server. The biggest offender right now are Splat Maps on terrain data. To investigate further, I have looked for ways to remove splat maps for testing, and the only way I could find was through the Terrain Toolbox.

Unfortunately, that does not seem to work, or it works in a way that I cannot figure out.

- Unity 2022.2.2f1
- Terrain Tools package 5.0.2

This is my workflow:
- Open a scene with a terrain with splat data
- Open Terrain Toolbox via Window > Terrain > Terrain Toolbox
- Open the Terrain Utilities tab
- Select the terrain in the scene hierarchy window, click Import from Selected Terrain
- The splat maps show up in the list as expected
- I select a splat map and click the - button below the splat map list, the splat map is removed from the list
- Repeat previous step until splat map list is empty
- I click Apply to Terrain
- Click Import from Selected Terrain

Result: The previously removed splat maps appear in the list again.

Clicking Reset Splatmaps instead does not make any difference.

Any advice is highly appreciated.

Thanks!