Layer weight painting on the landscape via blueprint

Does anyone know how I can paint the layer weight of a terrain using blueprint?

I want to create an editor tool that creates a spline and then textures the landscape in the interior of that spline. I have the first part working but have no clue about the second part (the texturing).
Even better if it can work with the Scriptable Editor Tool.

Thank you!

I’m doing a similar thing at the moment for rivers and lakes. You can use the Editor Apply Spline node to paint a texture layer under a spline. Works great for rivers, just figuring out how to use it for a closed loop spline like a lake now.

Thanks I will have a look!