I bought the rod for my sliding glass door to the deck and was going to add sheers behind solid drapes. I say was, because even with the rod brackets extended out to their full extension the grommets would challenge each other, so I would need to use a sheer that didn't have grommets, For a slider, a drape with a rod pocket, to me, wouldn't slide easy enough, plus I push the drapes to one end of the rod when open. The rods that sit on the brackets for a second curtain are in several pieces so that would require the center bracket to be installed.
This rod is very heavy duty and the drapes I have aren't heavy enough to warrant installing the middle support bracket, even with the width of a slider to my deck.