Two other issues:
When using a mask for brush when painting landscape, the mask has a rotation option, it’d be cool to be able to hold down a key on the keyboard and move the mouse forward/backward for rotating the mask. I’ve made the same request for increasing/decreasing brush radius and intensity.
Another problem with using landscape spline to create roads is if at any point one needs to delete the landscape, or export it, modify it a bit and re-import it, all the splines are lost and the work is gone. So that’s another reason to have spline decals.