If you mean for painting Landscape Spline problem, then I don’t need to - just create any Landscape on an empty map (even without material at all), make a Landscape Spline on it, then attach to its segments a mesh with a simple material. It don’t even need to have Vertex Color node in it, slowdowns will show up as well during painting. Very easy and quick to recreate.
In the material for my spline I use the vertex colour just as a mask in one Lerp. It works on a simple mesh, but on Landscape Spline paint doesn’t work at all.