AutoCAD .NET :: Passing Late-bound Variant Arrays

I have been attempting to pass a string array contained in a variant to the AutoCAD method AcadPlot.SetLayoutsToPlot.  I am using late binding without a Interop assembly because we have several versions of AutoCAD in this company and I would like to support all of them from the same code base.The method wants a variant that contains a string array passed byref.  The Microsoft documentation on COM interop from VB.NET makes it sound like the compiler will marshal it correctly by default, but it always throws a COMException (Exception from HRESULT: 0x80070057 (E_INVALIDARG)).

The stack trace shows it is trying to anyway:

StackTrace:
       at Microsoft.VisualBasic.CompilerServices.LateBinding.InternalLateCall(Object o, Type objType, String name, Object[] args, String[] paramnames, Boolean[] CopyBack, Boolean IgnoreReturn)
       at Microsoft.VisualBasic.CompilerServices.NewLateBinding.LateCall(Object Instance, Type Type, String MemberName, Object[] Arguments, String[] ArgumentNames, Type[] TypeArguments, Boolean[] CopyBack, Boolean IgnoreReturn)

But no matter how I code it I cannot get this variant array passed to AutoCAD.I have tried:

Imports System.Runtime.InteropServices
' VB default marshalling
Dim layoutarr = New Object() {"Layout1"}
doc.Plot.SetLayoutsToPlot(layoutarr)
' using a VariantWrapper
Dim layoutarr = New Object() {"Layout1"}
Dim wrapper As New System.Runtime.InteropServices.VariantWrapper(layoutarr)
doc.Plot.SetLayoutsToPlot(wrapper)
[code]...

As intensively as AutoCAD ActiveX uses variant arrays, I know this problem is going to come up again and again for me as I try to migrate code over to .NET.