While playing around with 4.11.1 I noticed that under "Scripting Files" I can create a new razor script based on C# or VB.NET, so I went ahead and put the VB.NET option to a test, assuming that if it's there it is supported.

First of all I created a c# script based on the "Navigation" template.
It worked just fine.
After that I created a new script, this time based on VB.NET and ported the navigation template to VB.NET.
When I try to save it I get this error:

C:\[InstallFolder]\macroScripts\634905081306513672_MainNavigationVB.vbhtml(28): error BC30456: 'Level' is not a member of 'System.Web.UI.WebControls.Parameter'.

Here is the Navigation templated ported to VB.NET:

@Inherits umbraco.MacroEngines.DynamicNodeContext
@Code



    Dim level = If(String.IsNullOrEmpty(Parameter.Level), 1, Integer.Parse(Parameter.Level))
    Dim ulClass = If(String.IsNullOrEmpty(Parameter.UlClass), "", String.Format(" class='{0}'", Parameter.UlClass))
    Dim parent = Model.AncestorOrSelf(level)
    If Not IsNothing(parent) then
        @<ul @Html.Raw(ulClass)>
            @For Each item In parent.Children.Where("Visible")
                Dim selected = If(Array.IndexOf(Model.Path.Split(","), item.Id.ToString()) >= 0, " class='selected'", "")
                @<li @Html.Raw(selected)>
                    <a href="@item.Url">@item.Name</a>
                 </li>
            Next                    
        </ul>
    End If

End Code

Looks like the VB.NET code is not grabbing the Parameter property as the C# one does. 
So, what am I missing?