Gray32Float and Rgb128Float not supported in TiffBitmapEncoder

I would like to report a bug:

Using WriteableBitmap.WritePixels this format can next be saved using BitmapEncoder.Frames.Add(BitmapFrame.Create(WriteableBitmap));

I can understand BitmapEncoder may not support this, but according to the original TIFF 6.0 specs, in Tiff should support these color formats.

I would like to be proved wrong, but have tested extensively. I'm happy to provide more details if needed, including code etc.

Thank you,