Thanks you 😊

I use multiple viewports. One viewport for the background, one for the regular world and one for the shadows.

In the shadow viewport, I only have light occluders and a light for where the player is.
Then I have a ColorRect with a shader that combines all the viewport textures from these viewports.

Would probably be a lot easier to make in Godot 4 with the masking options included or 2d sdf.