Been working on a custom Terrain shader in URP and noticed that the Terrain Tools preview package doesn’t use the terrain material’s ITerrainLayerCustomUI.OnTerrainLayerGUI(). Not exactly a bug but seems like a feature the tool should have
After some more playing it seems it started working after opening the material foldout for the first time and now I can’t reproduce it being broken. Really strange but its working now so ignore this