When I create an overlay in an idw, the overlay view lines (the Overlay layer) is always on top of the Visible lines layer.... Which to me is backwards. It sometimes makes the drawing hard to look at and difficult to read. I usually go an extra step and make a view rep to turn off the unwanted items. That is just something else that has to be maintained as the assembly is being developed/changed and could be avoided if the draw order was changed.
It would be better if the overlay layer was moved to be behind the overlay layer. Currently there is no way to change the draw order of the lines.