Unity. Change material standard shader blend mode.

Utils.cs

    //see https://github.com/Unity-Technologies/UnityCsReference/blob/9034442437e6b5efe28c51d02e978a96a3ce5439/Editor/Mono/Inspector/StandardShaderGUI.cs
    //blend mode 3 - transparent
    public static void SetupMaterialWithBlendMode(Material material, int blendMode)
    {
        var assembly = Assembly.GetAssembly(typeof(Editor));
        var type = assembly.GetType("UnityEditor.StandardShaderGUI");
        var method = type.GetMethod("SetupMaterialWithBlendMode");

        method.Invoke(null, new object[] {material, blendMode});
    }