You might want to look at Steve's Blinds. I learned of the website long ago here on GW and ordered several TDBU cellular shades. Steve's carries several manufacturers' products but we purchased "Steve's own" brand. I believe they are made by a subsidiary of Hunter Douglas but this may be incorrect. We already have several similar blinds in the Hunter Douglas brand and have found the Steve's product to be comparable in quality. Would definitely order from the company again. I am linking the results of a quick search on the website using made-up dimensions and specifying "Steve's own" brand. Please note that there are many other options available on the website, and you will need to carefully enter the particulars for your windows instead of relying on the numbers I used. There is an up-charge for the TDBU feature as well. The website is kind of junky and confusing but you can call and get some customer service assistance. Here is a link that might be useful: Steve's Blinds

The manufacturer will have a maximum width that they will make which may very well be less than 9'. When I was getting my wood blinds for my 5' window, I think I just came in under the wire for max width. Otherwise, I would have had to get 3 separate sections. Cell shades don't weigh so much, so that helps, but I suspect 9' may not be available. The mechanism -- top-down-bottom-up or just bottom-up -- may limit your choices as well at that width. I think my 5' limit was also because I wanted cordless.

And squirrels look so cute.... You Tube is your friend, check it out for step by step instruction videos for restringing roman shades. ML

I enquired about this in the past and was told it would require a third track. Thinking about that, where would the cord to operate the third track be located? Both left and right sides are already occupied. Cords can’t be too close or they’d tangle together, hence why they’re on the left and right. A third track might need to operate differently, perhaps similarity to how a top down bottom up Venetian operates with its tilting of the louvres. Perhaps this could happen with powered only blinds that didn’t have cords