I do not know when this might be completed. I have forwrded your question onto the development team to see if they have an idea.
It is straight-forward to do this using the DrawCellDisplayText event.
private void gridControl1_DrawCellDisplayText(object sender, GridDrawCellDisplayTextEventArgs e)
{
float w = e.Graphics.MeasureString(e.DisplayText, e.Style.GdipFont).Width;
if(w > e.TextRectangle.Width)
{
e.DisplayText = new string(''#'', e.DisplayText.Length);
}
}