How to reproduce:
1. Create a new Unity project
2. In the Hierarchy, right-click -> 3D Object -> Terrain
3. In the Inspector, switch to the "Paint Terrain" mode
4. Select any of the painting options (Set Height, Paint Holes, etc.)
5. Change the "Opacity" of the Brush and switch to the different painting option
6. Observe the "Opacity" field

Expected results: The Opacity is not carried over from the first painting option
Actual results: The Opacity is the same for all brushes even though it would be nice to have separate settings at least on some brushes

Reproducible with: 6000.0.58f1, 6000.2.5f1, 6000.3.0b2

Reproducible on: macOS Sequoia 15.6 (M1)
Not reproducible on: No other environment tested